There are a couple points that are significant about the boy finding his own drawings in the chest.
The chest was long the repository of things important to his mother. Finding his drawings in there showed him how his mother felt about him. He had created something that his mother deemed so important that she could not throw away.
The chest was also the repository of old things, things from the past. By finding his drawings in there, it was proof that his childhood was over, a thing from the past.
He uses rule 83 by changing his behavior
The option that contains an independent clause is the last example - While the team made their play, the frenzied crowd cheered them to victory. The independent clause here would be <em>the frenzied crowd cheered them to victory. </em>
Irony and a metaphor is the best answer to this
In a cave ? because thats where they are in the movies and in real life.