The Monkey King
Explanation:
The Monkey King was the character from American Born Chinese which is the best example of a round character. Option A is correct.
A round character refers to the direct opposite of a flat character. A round character is extremely realistic, behaving and speaking in a "real life" manner. The character is complex and becomes increasingly complex throughout the story.
A round character is capable of contradiction and shift with evidence of emotional and psychological development.
Hope this helps.