Rationalize the Denominator and Simplify $\frac { 3 } { \sqrt { x } + 4 }$

Multiple Choice

Rationalize the denominator and simplify. Assume that all variables represent positive real numbers.
- $\frac { 3 } { \sqrt { x } + 4 }$

A) $\frac { - 12 - 3 \sqrt { x } } { x + 16 }$
B) $\frac { - 12 + 3 \sqrt { x } } { x ^ { 2 } - 16 }$
C) $\frac { - 12 - 3 \sqrt { x } } { x - 16 }$
D) $\frac { - 12 + 3 \sqrt { x } } { x - 16 }$