Simplify the Expression $$\left( \frac { a ^ { - 5 } } { b ^ { - 3 } } \right) ^ { - 4 }$$

Multiple Choice

Simplify the expression. $$\left( \frac { a ^ { - 5 } } { b ^ { - 3 } } \right) ^ { - 4 }$$
Write the answer without using negative exponents. Assume that all variables are restricted to those numbers for which the expression is defined.

A) $\quad \frac { a ^ { 12 } } { b ^ { 20 } }$
B) $\quad \frac { a ^ { 20 } } { b ^ { 12 } }$
C) $\quad \frac { b ^ { 12 } } { a ^ { 20 } }$
D) $\quad \frac { b ^ { 20 } } { a ^ { 12 } }$