diff --git a/uroboros/command.py b/uroboros/command.py
index 1f15f8b..b32f61c 100644
--- a/uroboros/command.py
+++ b/uroboros/command.py
@@ -121,7 +121,7 @@ class Command(metaclass=abc.ABCMeta):
                 name=cmd.name,
                 description=cmd.long_description,
                 help=cmd.short_description,
-                parents=[o.get_parser() for o in cmd.options],
+                parents=[o.get_parser() for o in cmd.get_options()],
             )
             cmd.initialize(sub_parser)
 
@@ -129,7 +129,7 @@ class Command(metaclass=abc.ABCMeta):
         parser = argparse.ArgumentParser(
             prog=self.name,
             description=self.long_description,
-            parents=[o.get_parser() for o in self.options]
+            parents=[o.get_parser() for o in self.get_options()]
         )
         parser.set_defaults(func=self.run)
         return parser

`Command.get_options()` does not work well
### Expected

```python
class SomeOption(uroboros.Option):
    def build_option(self, parser):
        parser.add_argument('--opt', type=str)
        return parser

class HelloCommand(uroboros.Command):

    def get_options():
        return [SomeOption()]

HelloCommand().execute()
```

Now, `--opt` can be used.

### Actual

`--opt` does not be appeared in help message, and cannot parse it.


diff --git a/tests/test_command.py b/tests/test_command.py
index b80b64f..a7eb5f0 100644
--- a/tests/test_command.py
+++ b/tests/test_command.py
@@ -4,6 +4,7 @@ from unittest import mock
 
 import pytest
 
+from uroboros import Option
 from uroboros.errors import CommandDuplicateError
 from .base import RootCommand, SecondCommand, ThirdCommand
 
@@ -318,3 +319,22 @@ class TestCommand(object):
         for cmd in commands:
             key = "after_validate_{}".format(cmd.name)
             assert getattr(args, key, None) == cmd.value
+
+    def test_create_default_parser(self):
+        class Opt(Option):
+            def build_option(self, parser):
+                parser.add_argument("--test", type=str)
+                return parser
+
+        class Cmd(RootCommand):
+            options = [Opt()]
+
+        class Cmd2(RootCommand):
+            def get_options(self):
+                return [Opt()]
+
+        argv = ["--test", "test"]
+        for cmd in [Cmd(), Cmd2()]:
+            cmd_parser = cmd.create_default_parser()
+            args = cmd_parser.parse_args(argv)
+            assert args.test == 'test'

pip install -e .[dev]
parse_log_pytest
pytest
pytest flake8
3.7
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs @ file:///croot/attrs_1668696182826/work
certifi @ file:///croot/certifi_1671487769961/work/certifi
flake8==5.0.4
flit_core @ file:///opt/conda/conda-bld/flit-core_1644941570762/work/source/flit_core
importlib-metadata==4.2.0
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
mccabe==0.7.0
packaging @ file:///croot/packaging_1671697413597/work
pluggy @ file:///tmp/build/80754af9/pluggy_1648042572264/work
py @ file:///opt/conda/conda-bld/py_1644396412707/work
pycodestyle==2.9.1
pyflakes==2.5.0
pytest==7.1.2
tomli @ file:///opt/conda/conda-bld/tomli_1657175507142/work
typing_extensions @ file:///croot/typing_extensions_1669924550328/work
-e git+https://github.com/pddg/uroboros.git@45d0b03c86a75d96237cd885d37b8715bf5cfdfc#egg=uroboros
zipp @ file:///croot/zipp_1672387121353/work

name: uroboros
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - attrs=22.1.0=py37h06a4308_0
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2022.12.7=py37h06a4308_0
  - flit-core=3.6.0=pyhd3eb1b0_0
  - importlib_metadata=4.11.3=hd3eb1b0_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - packaging=22.0=py37h06a4308_0
  - pip=22.3.1=py37h06a4308_0
  - pluggy=1.0.0=py37h06a4308_1
  - py=1.11.0=pyhd3eb1b0_0
  - pytest=7.1.2=py37h06a4308_0
  - python=3.7.16=h7a1cb2a_0
  - readline=8.2=h5eee18b_0
  - setuptools=65.6.3=py37h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - tomli=2.0.1=py37h06a4308_0
  - typing_extensions=4.4.0=py37h06a4308_0
  - wheel=0.38.4=py37h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zipp=3.11.0=py37h06a4308_0
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - flake8==5.0.4
      - importlib-metadata==4.2.0
      - mccabe==0.7.0
      - pycodestyle==2.9.1
      - pyflakes==2.5.0
prefix: /opt/conda/envs/uroboros

tests/test_command.py::TestCommand::test_create_default_parser
tests/test_command.py::TestCommand::test_build_option[command0] tests/test_command.py::TestCommand::test_build_option[command1] tests/test_command.py::TestCommand::test_build_option[command2] tests/test_command.py::TestCommand::test_validate[command0] tests/test_command.py::TestCommand::test_validate[command1] tests/test_command.py::TestCommand::test_validate[command2] tests/test_command.py::TestCommand::test_increment_nest[command_set0] tests/test_command.py::TestCommand::test_increment_nest[command_set1] tests/test_command.py::TestCommand::test_increment_nest[command_set2] tests/test_command.py::TestCommand::test_register_parent[command_set0] tests/test_command.py::TestCommand::test_register_parent[command_set1] tests/test_command.py::TestCommand::test_register_parent[command_set2] tests/test_command.py::TestCommand::test_add_command[command_set0] tests/test_command.py::TestCommand::test_add_command[command_set1] tests/test_command.py::TestCommand::test_add_command[command_set2] tests/test_command.py::TestCommand::test_multiple_add_command[root_cmd0-add_commands0] tests/test_command.py::TestCommand::test_multiple_add_command[root_cmd1-add_commands1] tests/test_command.py::TestCommand::test_add_others tests/test_command.py::TestCommand::test_get_all_sub_commands[command_set0] tests/test_command.py::TestCommand::test_get_all_sub_commands[command_set1] tests/test_command.py::TestCommand::test_get_all_sub_commands[command_set2] tests/test_command.py::TestCommand::test_get_all_sub_commands[command_set3] tests/test_command.py::TestCommand::test_get_sub_commands[command_set0-argv0] tests/test_command.py::TestCommand::test_get_sub_commands[command_set1-argv1] tests/test_command.py::TestCommand::test_get_sub_commands[command_set2-argv2] tests/test_command.py::TestCommand::test_get_sub_commands[command_set3-argv3] tests/test_command.py::TestCommand::test_get_sub_commands[command_set4-argv4] tests/test_command.py::TestCommand::test_add_duplicate_command[command_set0] tests/test_command.py::TestCommand::test_add_duplicate_command[command_set1] tests/test_command.py::TestCommand::test_execute[command_set0-root tests/test_command.py::TestCommand::test_execute[command_set1-root tests/test_command.py::TestCommand::test_execute[command_set2-root-False] tests/test_command.py::TestCommand::test_execute[command_set3-root tests/test_command.py::TestCommand::test_execute[command_set4-root tests/test_command.py::TestCommand::test_execute[command_set5-root-False] tests/test_command.py::TestCommand::test_violates_validation_argv[command_set0-root tests/test_command.py::TestCommand::test_violates_validation_argv[command_set1-root tests/test_command.py::TestCommand::test_violates_validation_argv[command_set2-root tests/test_command.py::TestCommand::test_violates_validation_argv[command_set3-root tests/test_command.py::TestCommand::test_violates_validation_argv[command_set4-root tests/test_command.py::TestCommand::test_violates_validation_argv[command_set5-root tests/test_command.py::TestCommand::test_before_validate tests/test_command.py::TestCommand::test_pre_hook[commands0] tests/test_command.py::TestCommand::test_pre_hook[commands1] tests/test_command.py::TestCommand::test_pre_hook[commands2] tests/test_command.py::TestCommand::test_after_validate tests/test_command.py::TestCommand::test_pre_hook_validated[commands0] tests/test_command.py::TestCommand::test_pre_hook_validated[commands1] tests/test_command.py::TestCommand::test_pre_hook_validated[commands2]
uroboros/command.py
uroboros/command.py