Write a Formula for the General Term (The Nth Term) $- 8 , - 16 , - 32 , - 64 , - 128 , \ldots$

Multiple Choice

Write a formula for the general term (the nth term) of the geometric sequence.
- $- 8 , - 16 , - 32 , - 64 , - 128 , \ldots$

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