Let V Be the Volume of the Solid That Lies $y = - \sqrt { 9 - x ^ { 2 } }$

Multiple Choice

Let V be the volume of the solid that lies between planes perpendicular to the x-axis from x = -3 to x = 3. The cross-sections of this solid perpendicular to the x-axis run from $y = - \sqrt { 9 - x ^ { 2 } }$ to $y = \sqrt { 9 - x ^ { 2 } }$ and they are semicircles with diameters in the xy-plane. Then V is

A) $\frac { \pi } { 3 }$
B) $14 \pi$
C) $18 \pi$
D) $\frac { 7 \pi } { 3 }$
E) $\pi$