Answer:
see below
Step-by-step explanation:
If this is a multiple choice question, then the answer is:
"how the characters change"
But, if this is a written response question, then let me explain:
A theme is a message that the author is trying to relay to us as readers, whether its through a poem, book, novel, short story, or speech. If we are given 2 stories, then we need to find the characters and how they change throughout the given plot. This is because the theme is usually connected to the plot, and is usually emotional and the reader can relate to it. So, the character's reaction to the plot is like the reader's reaction, so we can use the character change to help us determine the theme.