Simplify the Expression Without a Calculator $3 ^ { - 6 }$

Multiple Choice

Simplify the expression without a calculator. $3 ^ { - 6 }$

A) $\frac { 1 } { 730 }$
B) $\frac { 1 } { 728 }$
C) $\frac { 1 } { 731 }$
D) $\frac { 1 } { 729 }$
E) $\frac { 1 } { 732 }$