The correct answer is: C) Round character
A round character refers to a character that is complex, at the same time the story develops this complexity increases as well, as a result the character won't be the same in the beggining than in the end. This kind of characters is close to a real person as he has the same doubts and internal conflicts as you or me. That is the reason it is associated with internal conflict, his/her feelings, fears, passions, etc are shown, when making a decission the round character is going to compare each consecuence. It contrasts with the flat character that is uncomplicated and doesn't really change through the story.