Perform the Indicated Operation and Write Your Answer with Positive $$\frac { m ^ { - 1 } + n ^ { - 1 } } { ( m n ) ^ { - 1 } }$$

Multiple Choice

Perform the indicated operation and write your answer with positive integer exponents.
- $$\frac { m ^ { - 1 } + n ^ { - 1 } } { ( m n ) ^ { - 1 } }$$

A) $- n + m$
B) $n - m$
C) $- n - m$
D) $n + m$