Simplify the Expression $\sqrt { \frac { 18 } { x } }$

Multiple Choice

Simplify the expression. Assume all variables represent positive real numbers.
- $\sqrt { \frac { 18 } { x } }$

A) $\frac { \sqrt { 3 x } } { x }$
B) $3 \sqrt { 2 x }$
C) $3 \sqrt { \frac { 2 } { x } }$
D) $\frac { 3 \sqrt { 2 x } } { x }$