Determine Whether the Sequence Is Geometric $- 1 , - 2 , - 4 , - 8 , \ldots$

Multiple Choice

Determine whether the sequence is geometric. If so, find the common ratio. $- 1 , - 2 , - 4 , - 8 , \ldots$

A) 2
B) $- 1$
C) $\frac { 1 } { 2 }$
D) $- 2$
E) not geometric