I put B and got this wrong, may I know the right answer with an explaination?

The slope of the graph gives the angular acceleration which is the rotational equivalent of tangential acceleration.
Recall, the formula for calculating net torque is expressed as
T = Ia
where
I represents rotational inertia
a represents angular acceleration
Given that I = 0.125
then, the correct option is
Yes because the slope of the graph multiplied by the rotational inertia is equal to the net torque on the edge of the disk