Find the Nth Term of the Geometric Sequence $- 8 , - 16 , - 32 , - 64 , - 128$

Multiple Choice

Find the nth term of the geometric sequence.
- $- 8 , - 16 , - 32 , - 64 , - 128$

A) $a _ { n } = - 8 \cdot 2 ^ { n }$
B) $a _ { n } = a _ { 1 } + 2 ^ { n }$
C) $a _ { n } = - 8 \cdot 2 ^ { n - 1 }$
D) $a _ { n } = - 8 \cdot 2 n$