Write the Word or Phrase That Best Completes Each Statement $\epsilon$

Write the word or phrase that best completes each statement or answers the question.
Provide the missing information.
-A model rocket is launched from a raised platform at a speed of 176 feet per second. Its height in fe $\epsilon$ given by
$h ( t ) = - 16 t ^ { 2 } + 176 t + 20 \quad ( t =$ seconds after launch $) .$
After how many seconds does the object reach its maximum height?

A) $7.5$ seconds
B) $2.75$ seconds
C) $5.5$ seconds
D) 20 seconds