Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Which Opponent has a Round of 4, and a Rules of thai boxing?

### Inputs:
table_name: table, columns: ['Result', 'Opponent', 'Method', 'Event', 'Date', 'Round', 'Time', 'Location', 'Rules']

### Response:
SELECT Opponent FROM table WHERE Round = 4 AND Rules = thai boxing