Find the Radius of Convergence of the Series $\sum _ { n = 1 } ^ { \infty } \frac { ( - 1 ) ^ { n } x ^ { 3 n + 7 } } { 3 n + 7 }$

Multiple Choice

Find the radius of convergence of the series $\sum _ { n = 1 } ^ { \infty } \frac { ( - 1 ) ^ { n } x ^ { 3 n + 7 } } { 3 n + 7 }$ .

A) 1
B) 3
C) 10
D) 4
E) 6