Take an example, f(x) = x2 - x + 1 so from this example we get f'''(x) = 2. So D) none of these is answer
I know this method only. But it was simple bcoz f(0) =1 means function is f(x)= something + 1. Then it was given f'(0)=-1 which means function can bef(x)= something -x + 1 and to contradict options I took x2. Somebody post other answer if there is some theorem or method for this question.