Simplify Assume That All Variables Represent Positive Real Numbers $\sqrt { 72 x ^ { 2 } }$

Multiple Choice

Simplify. Assume that all variables represent positive real numbers.
- $\sqrt { 72 x ^ { 2 } }$

A) $6 \sqrt { 2 x }$
B) $2 x ^ { 2 } \sqrt { 6 }$
C) $6 \times \sqrt { 2 }$
D) $72 \mathrm { x }$