Solve the Problem $t$ Is $s ( t ) = - 16 t ^ { 2 } + 192 t + 230$

Multiple Choice

Solve the problem.
-A rock is propelled upward from the top of a building 230 feet tall at an initial velocity of 192 feet per second. The function that describes the height of the rocket in terms of time $t$ is $s ( t ) = - 16 t ^ { 2 } + 192 t + 230$ . Determine the time at which the rock reaches its maximum height.

A) $9.6 \mathrm { sec }$
B) $4.8 \mathrm { sec }$
C) $12 \mathrm { sec }$
D) $6 \mathrm { sec }$