Which is an example of satire?

A.The family members in a short story have an elephant living in their dining room that they refuse to discuss, just as they refuse to deal with other problems.

B.A play about a deaf character includes jokes that are funnier in sign language, so audience members who don't know sign language are left out.

C.A film's teenage character rolls her eyes and says, "Sure, I'd love to," when her mother asks her to clean the toilet.

D.In a novel, the partners in a couple have good news they hide from each other, unaware that the other is doing the same thing.

I believe C is sarcasm not satire but I don't understand the difference between the other 3 answers. If you could explain the answer to me that would be great. Thanks.