Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_16 (opponent VARCHAR, round VARCHAR, rules VARCHAR)
### Question:
Which Opponent has a Round of 4, and a Rules of thai boxing?
### Answer:
SELECT opponent FROM table_name_16 WHERE round = "4" AND rules = "thai boxing"