Write with Positive Exponents $( - 64 ) ^ { - 2 / 3 }$

Multiple Choice

Write with positive exponents. Simplify if possible.
- $( - 64 ) ^ { - 2 / 3 }$

A) $- 16$
B) $\frac { 1 } { 16 }$
C) $- \frac { 1 } { 16 }$
D) $\frac { 128 } { 3 }$