Express Using Positive Exponents $x^{-2}$ A) $x^{2}$ B) $2 x$ C) $\frac{1}{x^{-2}}$ D) $\frac{1}{x^{2}}$

Express using positive exponents. Then simplify.
- $x^{-2}$

A) $x^{2}$
B) $2 x$
C) $\frac{1}{x^{-2}}$
D) $\frac{1}{x^{2}}$