Force changes with time so it can't be b.....and it's not based on the current. It's based on the coil itself which is initially parallel to the field so theta=0 . Therefore initial force is 0
11 is D
sin0=0 so force is minimum
as theta increases, force increases it is not constant till 90 degrees
sin90=1 so force is maximum
cos0=1 so initially torque is maximum
cos90=0 so torque is minimum
so its D
QED