Simplify $( 3 - 6 i ) ^ { 2 } - ( 3 + 6 i ) ^ { 2 }$

Multiple Choice

Simplify $( 3 - 6 i ) ^ { 2 } - ( 3 + 6 i ) ^ { 2 }$ and write the answer in standard form.

A) 0
B) $- 72 i$
C) $18 - 72 i$
D) $18 + 72 i$
E) $6 - 24 i$