Find a Formula for the Nth Term of the Sequence $0 , \frac { 2 } { 3 } , 0 , \frac { 2 } { 3 } , 0$

Multiple Choice

Find a formula for the nth term of the sequence.
- $0 , \frac { 2 } { 3 } , 0 , \frac { 2 } { 3 } , 0$ (alternating 0 's and $\frac { 2 } { 3 }$ 's)

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