Read these lines of poetry:

The wicked dragon breathed fire,
and its wings were black as coal.
But the knight's eyes were diamonds,
and he kept his self-control.

Which line contains a metaphor?

A.
"and its wings were black as coal."

B.
"and he kept his self-control."

C.
"The wicked dragon breathed fire,"

D.
"But the knight's eyes were diamonds,"