Write an Equation That Relates the Variables $\text { fourth }$

Write an equation that relates the variables. z is directly proportional to x and inversely proportional to the $\text { fourth }$ root of y

A) $z = \frac { k } { x ^ { 4 } \sqrt { y } }$
B) $z = x \sqrt [ 4 ] { k y }$
C) $z = \frac { 1 } { k x ^ { 4 } \sqrt { y } }$
D) $z = \frac { k x } { \sqrt [ 4 ] { y } }$
E) $z = k x \sqrt [ 4 ] { y }$