Simplify the Expression Without Using a Calculator $\log _ { 5 / 4 } \left( \frac { 256 } { 625 } \right)$

Multiple Choice

Simplify the expression without using a calculator.
- $\log _ { 5 / 4 } \left( \frac { 256 } { 625 } \right)$

A) $\frac { 1 } { 4 }$
B) 4
C) $- \frac { 1 } { 4 }$
D) $- 4$