Find the Intervals Where $f ( x ) = \frac { \log 9 x } { x }$

Multiple Choice

Find the intervals where $f ( x ) = \frac { \log 9 x } { x }$ is increasing and where it is decreasing.

A) increasing: $( 9 e , \infty )$ , decreasing: $( 0,9 e )$
B) increasing: $\left( 0 , \frac { e } { 9 } \right)$ , decreasing: $\left( \frac { e } { 9 } , \infty \right)$
C) increasing: $( 90 , \infty )$ , decreasing: $( 0,90 )$
D)
increasing: $\left( 0 , \frac { 9 } { 10 } \right)$ , decreasing: $\left( \frac { 9 } { 10 } , \infty \right)$