The answer is B.
Brutus believes Caesar's death was necessary for the good of Rome. However, the actions of the other men following Caesar's death (actions that are not noble and good, but rather greedy and selfish) lead Brutus to fear that perhaps Caesar's death was not for the good of Rome after all.
Just fake it, write something about how you didn't study for a test and you failed and you learned that you have to study for tests. Then you aced the final exam because you studied a lot and it really paid off. If you're in 9th grade or below, teachers will eat that sh*t up