The Height in Feet $h$ Of a Rocket in Flight Is Given by the Formula

Multiple Choice

The height in feet $h$ of a rocket in flight is given by the formula $h = - 16 t ^ { 2 } + 224 t$ , where $t$ is the time of the flight in seconds. How long will it take for the rocket to hit the ground?

A) 13 sec
B) 14 sec
C) 16 sec
D) 12 sec
E) 11 sec