#### Answer

Elliptical cylinder as shown in graph (a)

#### Work Step by Step

Since, we have $9^2+z^2=16$
This can be re-written as:
$\dfrac{y^2}{(4/3)^2}+\dfrac{z^2}{(4)^2}=1$
Thus, the above equation is a graph for Elliptical cylinder as shown in graph (a)