Let's see our options.
A.) Defines a simile.
B.) Yes. a metaphor is a statement that suggests comparisons by being indirect.
C.) If you don't know what a metaphor is, then why is the word "Metaphor" in this definition.
D.) No. It does not have to be in a poem.
Choice B is the best answer.
An example of a metaphor:
"You drive me up the wall!"