Find the Sum of the Infinite Geometric Series $\sum _ { n = 0 } ^ { \infty } 7 \left( \frac { 1 } { 3 } \right) ^ { n }$

Multiple Choice

Find the sum of the infinite geometric series. $\sum _ { n = 0 } ^ { \infty } 7 \left( \frac { 1 } { 3 } \right) ^ { n }$

A) $\frac { 2 } { 21 }$
B) $\frac { 2 } { 7 }$
C) $- \frac { 1 } { 3 }$
D) $\frac { 21 } { 2 }$
E) undefined