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 160 feet at an initial velocity of 144 feet per second, then its height h after t seconds is given by the function h(t) = -16t2 + 144t + 160. After how
Many seconds does the projectile land on the ground?

A) 5.0 seconds
B) 9.0 seconds
C) 10 seconds
D) 11 seconds