Write the Expression for the General (Or Nth)termrm $\mathbf { a } _ { \mathbf { n } } ,$

Multiple Choice

Write the expression for the general (or nth) termrm, $\mathbf { a } _ { \mathbf { n } } ,$ , of the geometric sequence.
-8, -16, 32, -64, 128,. . .

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