Find an Algebraic Expression That Is Equivalent to the Expression $$\cos ( \arcsin 2 x )$$

Multiple Choice

Find an algebraic expression that is equivalent to the expression.. $$\cos ( \arcsin 2 x )$$

A) $\sqrt { 4 x ^ { 2 } - 1 }$
B) $\frac { 1 } { \sqrt { 1 + 4 x ^ { 2 } } }$
C) $\sqrt { 1 + 4 x ^ { 2 } }$
D) $\sqrt { 1 - 4 x ^ { 2 } }$
E) $\frac { 1 } { \sqrt { 1 - 4 x ^ { 2 } } }$