Answer: Sonia's description of her impractical plans shows that she is more of a dreamer than a doer.
Explanation:
From the story, Sonia said that she was going to be a writer. She said that all she needed to do was to finish high school, go to college, and then get a job of some kind - something that would give her a source of income.
The above statement that "something that would give her a source of income" shows that she doesn't really have a plan to become a writer.
Then, she also said that she wasn't going to give up soccer practice and that as long as her friends didn't invite her to go out partying, she would write the great American novel. This means that if she's invited to party, she won't become a writer.
Therefore, the statement that explains how the plot of the story helps develop the main character is that Sonia's description of her impractical plans shows that she is more of a dreamer than a doer.
