Answer:
The answer is: B. Respectful.
Step-by-step explanation:
An antonym is the opposite, exactly the opposite. Having said this and in this case, the word derisive means "mocking", it's an adjective which tells someone makes jokes/fun of someone/something. So as you can see now, respectful is the opposite. Because uncertain is confused and has nothing to do with "derisive" , while humorous means to be funny or comic, but not precisely in a "rude" or "disrespectful" way, as a derisive person.