The height (h) of a fireball launched from a Roman candle with an initial velocity of 64 feet per second is given by the equation h(t) = -16t^2 + 64t, where t is time in seconds after launch. Use the graph of this function to answer the questions. Estimate the time when the fireball is at its maximum height.

A. 2.3 seconds

B. 2 seconds

C. 0 seconds

D. 4 seconds