You toss a ball straight upward, in the positive direction. The ball falls freely under the influence of gravity. At the highest point in the ball’s motion,

A、 its velocity is zero and its acceleration is zero.;
B、its velocity is zero and its acceleration is positive (upward).;
C、its velocity is zero and its acceleration is negative (downward).;
D、its velocity is positive (upward) and its acceleration is zero.