Find the Volume of the Described Solid $x ^ { 2 } + y ^ { 2 } \leq 9$

Multiple Choice

Find the volume of the described solid.
-The base of the solid is the disk $x ^ { 2 } + y ^ { 2 } \leq 9$ . The cross sections by planes perpendicular to the $y$ -axis between $y = - 3$ and $y = 3$ are isosceles right triangles with one leg in the disk.

A) 90
B) 18
C) 72
D) 144