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.
- $\frac { 1 } { 7 } , \frac { 1 } { 49 } , \frac { 1 } { 343 } , \frac { 1 } { 2401 } , \ldots$

A) $a _ { n } = \frac { 1 } { 7 } + \frac { 1 } { 7 } ( n - 1 )$
B) $a _ { n } = \left( \frac { 1 } { 7 } \right) ^ { n - 1 } - \frac { 6 } { 49 }$
C) $a _ { n } = \frac { 1 } { 7 } - \frac { 6 } { 49 } ( n - 1 )$
D) $\mathrm { a } _ { \mathrm { n } } = \frac { 1 } { 7 } \left( \frac { 1 } { 7 } \right) ^ { n - 1 }$