Find a General Term A_n for the Geometric Sequence $\frac { 1 } { 2 } , 2,8 , \ldots$

Multiple Choice

Find a general term a_n for the geometric sequence.
- $\frac { 1 } { 2 } , 2,8 , \ldots$

A) $a _ { n } = \frac { 1 } { 2 } + \frac { 3 } { 2 } ( n - 1 )$
B) $a _ { n } = \frac { 1 } { 2 } + 4 ( n - 1 )$
C) $a _ { n } = \left( \frac { 1 } { 2 } \right) ^ { n - 1 } + \frac { 3 } { 2 }$
D) $a _ { n } = \frac { 1 } { 2 } ( 4 ) ^ { n - 1 }$