The correct answer should be A)
The conflict that consumes Brutus throughout the whole play finally settles when Brutus, consumed by the horror and the realization that by killing Caesar he did not save Rome, but only left it in the midst of a horrible civil war.
The tragedy is that despite the sacrifice of his moral values and his friendship, for the good of the Rome, and what he believed to be it's salvation, eventually it was precisely that decision that resulted in the destruction of Rome.