David, a platform diver, dives into the pool during practice. The height of David above the water at any given time, s, can be modeled by the quadratic function h(s).

Each of the following functions is a different form of the quadratic model for the situation above. Which form would be the most helpful if attempting to determine the time required for David to enter the water?

A. h(s) = -4.9(s - 2)(s + 1)

B. h(s) = -4.9s(s - 1) + 9.8

C. h(s) = -4.9(s - 0.5)2 + 11.025

D. h(s) = -4.9s2 + 4.9s + 9.8