diff --git a/nipype/interfaces/mrtrix3/preprocess.py b/nipype/interfaces/mrtrix3/preprocess.py
index ca5996bea..740513194 100644
--- a/nipype/interfaces/mrtrix3/preprocess.py
+++ b/nipype/interfaces/mrtrix3/preprocess.py
@@ -27,7 +27,7 @@ class ResponseSDInputSpec(MRTrix3BaseInputSpec):
         'tournier',
         'tax',
         argstr='%s',
-        position=-6,
+        position=1,
         mandatory=True,
         desc='response estimation algorithm (multi-tissue)')
     in_file = File(
@@ -74,7 +74,7 @@ class ResponseSD(MRTrix3Base):
     >>> resp.inputs.algorithm = 'tournier'
     >>> resp.inputs.grad_fsl = ('bvecs', 'bvals')
     >>> resp.cmdline                               # doctest: +ELLIPSIS
-    'dwi2response -fslgrad bvecs bvals tournier dwi.mif wm.txt'
+    'dwi2response tournier -fslgrad bvecs bvals dwi.mif wm.txt'
     >>> resp.run()                                 # doctest: +SKIP
     """
 

Mrtrix3 `dwi2response` - bad algorithm argument position
### Summary

Th Mrtrix3 `dwi2response` CL wrapper generates the following runtime error:
```shell
dwi2response:
mrinfo: [ERROR] no diffusion encoding information found in image "<DWI_FILE>"
dwi2response: [ERROR] Script requires diffusion gradient table: either in image header, or using -grad / -fslgrad option
```
It turns out that the command generated by `nipype` does not respect (my version of) the Mrtrix3 CL format.

### Actual behavior

Generated command (not runnable):
```shell
dwi2response -fslgrad <BVEC_FILE> <BVAL_FILE> -mask <MASK_FILE> tournier <WM_FILE>
```

### Expected behavior

Runnable command:
```shell
dwi2response tournier -fslgrad <BVEC_FILE> <BVAL_FILE> -mask <MASK_FILE> <WM_FILE>
```

### Environment

- `MRtrix 3.0_RC2-117-gf098f097    dwi2response     bin version: 3.0_RC2-117-gf098f097`
- `Python 2.7.12`
- `nipype v1.0.0`
 

### Quick and dirty solution

I'm really not sure how clean it is, but it worked for me; in the `ResponseSDInputSpec` class, I changed `position=-6` to `position=1` in the `algorithm` traits.


diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py b/nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py
index 29a89f097..01104d2d2 100644
--- a/nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py
@@ -8,7 +8,7 @@ def test_ResponseSD_inputs():
         algorithm=dict(
             argstr='%s',
             mandatory=True,
-            position=-6,
+            position=1,
         ),
         args=dict(argstr='%s', ),
         bval_scale=dict(argstr='-bvalue_scaling %s', ),

pip install -e .[dev]
parse_log_pytest
requirements.txt
pytest
apt-get update apt-get install -y gcc
3.6
requirements.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs==22.2.0
certifi==2021.5.30
click==8.0.4
configparser==5.2.0
decorator==4.4.2
funcsigs==1.0.2
future==1.0.0
importlib-metadata==4.8.3
iniconfig==1.1.1
isodate==0.6.1
lxml==5.3.1
mock==5.2.0
networkx==2.5.1
nibabel==3.2.2
-e git+https://github.com/nipy/nipype.git@168dfee8862e3a635d8fd6f0f4469ad0950e55b9#egg=nipype
numpy==1.19.5
packaging==21.3
pluggy==1.0.0
prov==1.5.0
py==1.11.0
pydot==1.4.2
pydotplus==2.0.2
pyparsing==3.1.4
pytest==7.0.1
python-dateutil==2.9.0.post0
rdflib==5.0.0
scipy==1.5.4
simplejson==3.20.1
six==1.17.0
tomli==1.2.3
traits==6.4.1
typing_extensions==4.1.1
zipp==3.6.0

name: nipype
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
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - 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
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - attrs==22.2.0
      - click==8.0.4
      - configparser==5.2.0
      - decorator==4.4.2
      - funcsigs==1.0.2
      - future==1.0.0
      - importlib-metadata==4.8.3
      - iniconfig==1.1.1
      - isodate==0.6.1
      - lxml==5.3.1
      - mock==5.2.0
      - networkx==2.5.1
      - nibabel==3.2.2
      - numpy==1.19.5
      - packaging==21.3
      - pluggy==1.0.0
      - prov==1.5.0
      - py==1.11.0
      - pydot==1.4.2
      - pydotplus==2.0.2
      - pyparsing==3.1.4
      - pytest==7.0.1
      - python-dateutil==2.9.0.post0
      - rdflib==5.0.0
      - scipy==1.5.4
      - simplejson==3.20.1
      - six==1.17.0
      - tomli==1.2.3
      - traits==6.4.1
      - typing-extensions==4.1.1
      - zipp==3.6.0
prefix: /opt/conda/envs/nipype

nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py::test_ResponseSD_inputs
nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py::test_ResponseSD_outputs
nipype/interfaces/mrtrix3/preprocess.py
nipype/interfaces/mrtrix3/preprocess.py