Answer: Option 3: Prefieren las películas de terror.
Explanation: Here the question is:
Qué prefieren tus amigos, las películas románticas o las películas de terror?
wich can be translated to:
"What do your friends, romantic movies or horror movies prefer?"
so the answer should start with a "them" or something like that.
the options are:
1) Preferimos las películas de terror. (We prefer horror movies.) this option can be discarded, because the one that is answering is including himself in the answer.
2) Prefieren comer. (They prefer to eat.) this starts correct, but actually does not answer the question.
3) Prefieren las películas de terror. (They prefer horror movies.)
This starts correctly and answers the question, so this is the correct option.
