Which statement best describes Colin's character in The Secret Garden?

A. Colin is a round, dynamic character whose role is to be the opposite of Dickon.

B.Colin is a flat, static character whose role is to be the opposite of Dickon.

C. Colin is a flat, static character who changes because of his interaction with Mary and Dickon.

D. Colin is a round, dynamic character who changes because of his interaction with Mary and Dickon.

PLEASE HELP AND ONLY ANSWER IF YOU ARE 100% SURE!! THANKS