Rationalize the Denominator $\frac { \sqrt { 81 } } { \sqrt { 10 } }$

Multiple Choice

Rationalize the denominator. Assume all variables represent positive real numbers.
- $\frac { \sqrt { 81 } } { \sqrt { 10 } }$

A) 109
B) $\frac { 9 \sqrt { 10 } } { 10 }$
C) $\frac { 81 \sqrt { 10 } } { 10 }$
D) $9 \sqrt { 10 }$