Simplify the Expression $\sqrt { - 81 } \cdot \sqrt { - 3 }$

Multiple Choice

Simplify the expression.
- $\sqrt { - 81 } \cdot \sqrt { - 3 }$

A) $- 27$
B) $9 \sqrt { 3 }$
C) $- 9 \sqrt { 3 }$
D) $9 \sqrt { - 3 }$