Easy, now many might not know certain formulas of cylinders.
But, for this equation we must use the formula:
h= \frac{V}{ \pi r^{2} }
It's saying to find the Height (h) divide the volume by \pi and the radius squared.
So, plug it in,
(It's trying to trick you by saying 187.5 \pi , but mutiply it to get 589)
h= \frac{589}{ \pi 6.25}
which is
h= \frac{589}{19.6}
h=30
Thus,your answer is 30. (A)