an object that is moving must have a change in
a) its speed.
b) its position.
c) its acceleration.
d) its applied force.

B ) position

Explanation:

speed shows how much of a distance the object is moving per unit timeposition is the place where the object is locatedacceleration is the rate of change of velocity of an object with the timeapplied force here means the force that is acting on the object

moving object can have a constant speed ,constant acceleration and no change in the applied force

(when there is no applied force on the object  ,it keep its motion uninterruptedly - Newton's first law of motion )

But if an object is moving , it must change its position as if it is still remain in the same position , there can never be a motion at all

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.