Translation:Why does he think that violence is the answer?
"Why does he think that violence will be an answer?" - why not?
Because there's no future tense in the sentence, as far as I can see? I think that would have to be למה הוא חושב שאלימות תהיה התשובה. (Non-native disclaimer firmly in place ;)
טוב. מסכים איתך
Also because התשובה has the article ה at its beginning, indicating "the answer."