Solve the Problem $h ( t ) = - 16 t ^ { 2 } + 112 t + 20$

Multiple Choice

Solve the problem.
-A model rocket is launched from a raised platform at a speed of 112 feet per second. Its height in feet is given by $h ( t ) = - 16 t ^ { 2 } + 112 t + 20$ t = seconds after launch) . After how many seconds does
The object reach its maximum height?

A) 5.5 seconds
B) 20 seconds
C) 1.75 seconds
D) 3.5 seconds