Rationalize the Denominator and Simplify $\frac { \sqrt { 3 } } { \sqrt { 7 } }$

Multiple Choice

Rationalize the denominator and simplify. Assume that all variables represent positive real numbers.
- $\frac { \sqrt { 3 } } { \sqrt { 7 } }$

A) $\frac { \sqrt { 21 } } { 7 }$
B) $\sqrt { 21 }$
C) $\frac { \sqrt { 21 } } { 49 }$
D) $\sqrt { 3 }$