An example of a "caustic" remark?

Question

I know it means sarcastic, or stinging. But i can't think of a good one as an example for my english flash cards. any help?

Answer 1

Mrs. Smith uses constructive, not caustic, criticism when she grades her students' papers.

Answer 2

hostile, cutting, insulting, and biting are a few that come to mind.

Answer 3

'Ya right'

or 'As if '=]