Given a statement and question, generate the answer to the question such that the answer is contained in the statement.

statement: The flu is not affected by drugs, only a vaccine, question: What is the only drug that affects the flu?
vaccine

statement: a cat requires vision for seeing food animals, question: What does a cat require vision for seeing?
food animals

statement: signals can cause the brain to feel pain, question: What can signals cause the brain to feel?

pain