Answer:
c)
Explanation:
When a ball is tossed upward, it rises due to the initial velocity which points upward (so it is positive if we choose the upward direction as positive), but once released, the only force (neglecting air resistance) acting on the ball is gravity.
This force is due to the mass of the Earth, and produces an acceleration in the same direction than the force, which is always downward, so in this case is negative.
As it has opposite direction to the velocity, causes the ball to slow down until it reach to a point when momentarily comes to an stop, and then changes direction falling with negative velocity, so it speeds up as it has the same sign than acceleration, that it is always present.