A penny rides on top of a piston as it undergoes vertical simple harmonic motion with an amplitude of 4.0 cm. If the frequency is low, the penny rides up and down without difficulty. If the frequency is steadily increased, there comes a point at which the penny leaves the surface.
1) At what point in the cycle does the penny first lose contact with the piston?
A. midpoint moving up
B. midpoint losing down
C. highest point
D. lowest point