Find an Equation in Rectangular Coordinates for the Equation Given $r = 4 z$

Multiple Choice

Find an equation in rectangular coordinates for the equation given in cylindrical coordinates. $r = 4 z$

A) $x ^ { 2 } + y ^ { 2 } = \frac { z } { 4 }$
B) $x ^ { 2 } + y ^ { 2 } = \frac { y } { 4 }$
C) $x ^ { 2 } + z ^ { 2 } = 4 y$
D) $x ^ { 2 } + y ^ { 2 } = 16 z ^ { 2 }$
E) $x ^ { 2 } + y ^ { 2 } = 4 z$