Answer:
I would say the answer is A.
But correct me if im wrong
He's the most sensitive one, and all the greasers pick on him - but in a friendly way. The Socs find it easier to target him and they even put a blade on him once. Ponyboy is also the youngest from the gang.
Mother are naturally countable nouns, since we can, clearly, count mothers
This is a theme. The difference between those two is that the plot is similar to the storyline, whereas themes are general thoughts being analyzed. In this case, this is a theme, whereas something more detailed with description of events would be a plot.