Write the Expression as a Single Logarithm with Coefficient 1 $a \neq 1 \text { and } b \neq 1$

Multiple Choice

Write the expression as a single logarithm with coefficient 1. Assume all variables represent positive real numbers with $a \neq 1 \text { and } b \neq 1$ .
- $3 \log _ { a } x - 9 \log _ { a } z ^ { 2 }$

A) $\frac { \log _ { a } x ^ { 3 } } { \log _ { a } z ^ { 18 } }$
B) $\log _ { a } \left( \frac { x ^ { 3 } } { z ^ { 11 } } \right)$
C) $\log _ { a } \left( \frac { x ^ { 3 } } { z ^ { 18 } } \right)$
D) $\log _ { a } \left( \frac { 3 x } { 9 z ^ { 2 } } \right)$