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 $a \neq 1 \text { and } b \neq 1$ .
- $4 \log _ { a } m - \log _ { a } n$

A) $\log _ { a } \left( \frac { m ^ { 4 } } { n } \right)$
B) $\log _ { a } \left( m ^ { 4 } - n \right)$
C) $\log _ { a } \left( \frac { 4 m } { n } \right)$
D) $\log _ { a } m ^ { 4 } \div \log _ { a } n$