Simplify the Expression $$\left( \frac { r ^ { 5 } r ^ { - 1 } } { r ^ { 3 } r ^ { - 3 } } \right) ^ { 2 }$$

Multiple Choice

Simplify the expression. $$\left( \frac { r ^ { 5 } r ^ { - 1 } } { r ^ { 3 } r ^ { - 3 } } \right) ^ { 2 }$$
Write the answer without using negative exponents. Assume that the variable is restricted to those numbers for which the expression is defined.

A) $r ^ { 2 }$
B) $\quad r ^ { 8 }$
C) $\quad r ^ { 0 }$
D) $\quad r ^ { 12 }$