During Tom Robinson's trial, and his experiences with Dill and Mrs. Dubose and Boo Radley, They begin to see that Jem<span> has become more thoughtful about life.</span>
The only article among these options is an, and that is the correct answer - <em>an </em>is the indefinite article.
It, her, and that are pronouns.
A. Metaphor
A metaphor is a direct comparison