A metal ball rolls from rest at Point A down the track to Point E as shown below. At which point in the picture above is the velocity at its greatest?

Explanation:

Velocity is at its greatest when kinetic energy is at its max which is when all the ball's energy has been transformed from potential energy to kinetic energy which is at the lowest point in its travels (assuming the ball is rolling down a ramp). You have no picture here so this answer is a general one, not a specific one.

it is called kinetic energy