Solve the Problem $21 \mathrm{~m} / \mathrm{s}$ , Its Height After $t$

Multiple Choice

Solve the problem.
-If a rock is thrown vertically upward from the surface of the moon at a speed of $21 \mathrm{~m} / \mathrm{s}$ , its height after $t$ seconds will be $s(t) =21 t-0.8 t^{2}$ meters. Find its height after 6 seconds.

A) 90.0 meters
B) 125.2 meters
C) 102.96 meters
D) 97.2 meters