Write a Formula for the General Term (The Nth Term) $$\frac { 1 } { 8 } , - \frac { 1 } { 40 } , \frac { 1 } { 200 } , - \frac { 1 } { 1000 } , \ldots$$

Multiple Choice

Write a formula for the general term (the nth term) of the geometric sequence.
- $$\frac { 1 } { 8 } , - \frac { 1 } { 40 } , \frac { 1 } { 200 } , - \frac { 1 } { 1000 } , \ldots$$

A) $a _ { n } = \frac { 1 } { 8 } - \frac { 1 } { 5 } ( n - 1 )$
B) $a _ { n } = \frac { 1 } { 5 } \left( - \frac { 1 } { 8 } \right) ^ { n - 1 }$
C) $a _ { n } = \frac { 1 } { 8 } \left( - \frac { 1 } { 5 } \right) ^ { n - 1 }$
D) $a _ { n } = \left( \frac { 1 } { 8 } \right) ^ { n - 1 } - \frac { 3 } { 20 }$