Find All Fixed Points for the Function by Setting the Function

Multiple Choice

Find all fixed points for the function by setting the function equal to x and solving the resulting equation for x.
-If a projectile is launched upward from a height of 32 feet at an initial velocity of 64 feet per second, then its height after t seconds is given by the function $h ( t ) = - 16 t ^ { 2 } + 64 t + 32$

A) 1 seconds
B) 2 seconds
C) 4 seconds
D) 8 seconds