The Potential Energy Function Shown in the Above Figure

The potential energy function shown in the above figure

A) applies to any system undergoing small oscillations about a position of stable equilibrium.
B) shows the classical turning points ±A.
C) tells that where -A < x < +A, the total energy is greater than the potential energy.
D) indicates that U(x) is directly proportional to x².
E) All of these are correct.