Express the Following Expression in Simplest Radical Form $\sqrt { 12 x + 8 y }$

Multiple Choice

Express the following expression in simplest radical form. All variables represent positive real numbers. $\sqrt { 12 x + 8 y }$

A) $2 \sqrt { 3 x + 2 y }$
B) $4 \sqrt { 5 x y }$
C) $4 \sqrt { 3 x + 2 y }$
D) $2 \sqrt { x + y }$