Express as the Logarithm of a Single Expression $$\left( \log _ { a } x - \log _ { a } y \right) + 2 \log _ { a } z$$

Multiple Choice

Express as the logarithm of a single expression. Assume that variables represent positive numbers.
- $$\left( \log _ { a } x - \log _ { a } y \right) + 2 \log _ { a } z$$

A) $\log _ { a } x z ^ { 2 } y$
B) $\log _ { a } \frac { x } { z ^ { 2 } v }$
C) $\log _ { a } \frac { 2 x z } { y }$
D) $\log _ { a } \frac { x z ^ { 2 } } { y }$