Write the Expression with Only Positive Exponents and Evaluate If $4 ^ { - 2 }$

Multiple Choice

Write the expression with only positive exponents and evaluate if possible. Assume all variables represent nonzero real
numbers.
- $4 ^ { - 2 }$

A) $\frac { 1 } { 16 }$
B) $- 16$
C) $- 8$
D) $- \frac { 1 } { 16 }$