What is Huck Finn's biggest problem in the novel, and how is it resolved?

A.
He owes many people in town money, but he eventually finds the treasure and pays them back.

B.
No one in town really cares about him, but the Widow Douglas eventually adopts him.

C.
He gets lost in the cave with Injun Joe, but Tom rescues him.

D.
He wants to learn how to read and write, but no one in town will teach him.