Express the Following Expression in Simplest Radical Form $\sqrt { 12 x }$

Multiple Choice

Express the following expression in simplest radical form. All variables represent positive real numbers. $\sqrt { 12 x }$

A) $2 \sqrt { 3 x }$
B) $2 x \sqrt { 3 }$
C) $4 \sqrt { 3 x }$
D) $2 \sqrt { x }$