Which sentence best expresses the central point of the selection?

A、Although Paul Logan was a target of other student’s abuse when he was a young boy, their attacks stopped as he grew taller and stronger.;
B、When Logan moved to a different school, he discovered that another student, George, was the target of more bullying than he was.;
C、Logan’s experience of being bullied and his shame at how he treated George eventually made him speak up for someone else who was teased.;
D、Logan is ashamed that he did not stand up for George when George was being attacked by a bully on the playground.