A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at an equal shoulder level) by the catcher. At what point is the ball's speed at a minimum? (air resistance is negligible)

a) just after leaving the center fielder's hand
b) just before arriving at the catcher's mitt
c) at the top of the trajectory
d) speed is constant during entire trajectory
e) both a and b are correct