Which of the following should not be taken literally and must be understood as a whole?

A. conflict

B. idiom

C. characterization

D. interpretation

B. Idioms should not be taken literally and must be understood as a whole.

For example: it's raining cats and dogs.

It's not really raining cats and dogs - you need to know this idiom in order to understand that it means there are some heavy rains outside.