A ball is launched from level ground into the air and moves along the trajectory shown in the diagram. At points $Q$, $R$, $S$ and $T$, the ball has kinetic energies $E_Q$, $E_R$, $E_S$ and $E_T$ respectively. The diagram shows the height above the ground of each of these four points. Air resistance may be ignored. Which difference between the kinetic energies is the smallest?
- A$E_Q - E_S$
- B$E_S - E_R$
- C$E_T - E_Q$
- D$E_T - E_R$