Multiple Choice Question

What is the purpose of the sentence below?

At six feet tall and 285 pounds, John is a bear of a man.
A.
It is a metaphor comparing John to a bear because he lives in the woods.

B.
It is a simile explaining how John is like a bear because he is a big man.

C.
It is a metaphor comparing John to a bear because he is a big man.

D.
It is a simile explaining how John is like a bear because he lives in the woods.

C. It is a metaphor comparing John to a bear because he is a big man.