Simplify the Expression $\frac { z ^ { - 7 } } { z ^ { - 5 } }$

Multiple Choice

Simplify the expression. Write the result without using negative exponents. (Assume all variables represent nonzero
real numbers.)
- $\frac { z ^ { - 7 } } { z ^ { - 5 } }$

A) $\frac { 1 } { z ^ { 2 } }$
B) $\frac { 1 } { z ^ { - 2 } }$
C) $z ^ { 2 }$
D) $\mathrm { z } ^ { 12 }$