Find an Algebraic Expression That Is Equivalent to the Expression $\sec ( \arctan 4 x )$

Multiple Choice

Find an algebraic expression that is equivalent to the expression. $\sec ( \arctan 4 x )$

A) $\sqrt { 16 x ^ { 2 } + 1 }$
B) $\sqrt { 1 - 16 x ^ { 2 } }$
C) $\frac { \sqrt { 16 x ^ { 2 } - 1 } } { 16 x ^ { 2 } - 1 }$
D) $\sqrt { 16 x ^ { 2 } - 1 }$
E) $\frac { \sqrt { 16 x ^ { 2 } + 1 } } { 16 x ^ { 2 } + 1 }$