What are fish heads good for?

Question

1. They are good for the brain.
2. They are good for brains.
3. They are good for a brain.
4. They are good for our brain.
5. They are good for our brains.
(Which answers are correct?)

Answer 1

1 and 5 are correct.

Answer 2

Thank you.
"The brain' is in the generic use, isn't it?

Answer 3

Yes, that's right.