If the charges of A and B are the same, the coulomb force between AB is repulsive force, and the direction and speed of the force are no longer in a straight line, then the ball B must move in a curve. With the increasing distance between AB, the coulomb force between AB and AB becomes smaller and smaller, so the speed of ball B becomes larger and smaller.

If A and B are heterogeneous charges, and the coulomb force between AB is gravity, when the coulomb force between AB is just equal to the centripetal force, the ball B will make uniform circular motion around the ball A.. At this time, the speed and acceleration of ball B will remain unchanged. When the coulomb force between AB is greater than the required centripetal force, the ball B will move centripetally, and the speed and acceleration will increase. When the coulomb force between AB is less than the required centripetal force, the ball B will do centrifugal motion, which has both speed and acceleration.

The choice of this question is wrong, so C.