Final answer:
The correct sentence has a semicolon to separate two independent clauses.
Step-by-step explanation:
The sentence that has correct punctuation is: Tom likes to swim; he doesn't like to sunbathe. The correct punctuation in this sentence is the semicolon (;) which is used to separate two closely related independent clauses. It is used when a stronger break is needed than a comma but not as strong as a period. In this case, the semicolon helps to show the contrast between Tom's likes and dislikes.
Learn more about Punctuation in English sentences