Rewrite the Ratio as a Ratio of Natural Logarithms and Simplify

Multiple Choice

Rewrite the ratio as a ratio of natural logarithms and simplify.
- $\frac { \log _ { 2 } x } { \log _ { 16 } x }$

A) $\frac { 1 } { 2 ^ { 3 } }$
B) $2 ^ { 3 }$
C) $\ln 4$
D) 4