I believe the answer is A because commas shouldn't come after the world and in answer B and D. Answer C has no commas and therefore cannot be the correct answer.
The plot is about how middle schoolers evolve. The setting of the school shows the everyday life of the main middle schooler going through the struggles of being a preteen and the preparation for high school. (If this doesn’t help google the plot of the story and think about the setting and the the relation.)
Sight because without sight you can’t imagine much