(A) sorrowful is the correct answer
The answer would be B because the antagonist of the story is the one who opposes someone or something.
Since its dealing with economics I would say C.
No you do not need a comma on this sentence here.
This paragraph is all about the impact verbs have in sentences, and how you should use them in your own writing. The implied main idea is: Use strong verbs in your writing since they are the most important!