A Golf Ball Thrown Directly Upwards from the Surface of the Moon

Multiple Choice

A golf ball thrown directly upwards from the surface of the moon with an initial velocity of 20 meters per second and will attain a height of $s(t) =-0.8 t^{2}+20 t$
meters in t seconds.How fast is the golf ball going at its high point?

A) 0 meters/sec
B) -0.8 meters/sec
C) 20 meters/sec
D) -20 meters/sec