Which of the following examples represents a flat character
A. Delves remains the fun loving goofy neighbor and friend to the main character Dallas throughout the story
B. Jon begins his cross country cycling trip positive and excited about the experience. By the end of the trip he is bitter and exhausted
C. Madeline constantly encounters difficulty when she tries to work on her twin sister Margo because their personalities are opposites
D. Ryan strives to gain acceptance at her new school despite being very different from the other students