Write a Formula for the General Term (The Nth Term) $2 , - 4,8 , - 16,32 , \ldots$

Multiple Choice

Write a formula for the general term (the nth term) of the geometric sequence.
- $2 , - 4,8 , - 16,32 , \ldots$

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