A Right Circular Cylinder Is Obtained by Revolving the Region $x = r$

Multiple Choice

A right circular cylinder is obtained by revolving the region enclosed by the line $x = r$ , the $x$ -axis, and the line $y = h$ , about the $y$ -axis. Find the volume of the cylinder.

A) $\pi \mathrm { rh }$
B) $2 \pi r ^ { 2 } \mathrm {~h}$
C) $\pi \mathrm { rh } ^ { 2 }$
D) $\pi r ^ { 2 } h$