Pick the correct statements : (a) Average speed of a particle in a given time is never less than the magnitude of the average velocity.

Pick the correct statements :
(a) Average speed of a particle in a given time is never less than the magnitude of the average velocity.

(b) It is possible to have a situation in which |dv/dt|≠ 0 but d/dt |v|=0

(c) The average velocity of a particle is zero in a time interval. It is possible that the instantaneous velocity is never zero in the interval.

(d) The average velocity of a particle moving on a straight line is zero in a time interval. It is possible that the instantaneous velocity is never zero in the interval. (Infinite accelerations are not allowed.)