Find the Radius of Convergence Of $\sum _ { n = 0 } ^ { \infty } \frac { n ! } { 4 ^ { n } } ( x + 3 ) ^ { n }$

Multiple Choice

Find the radius of convergence of $\sum _ { n = 0 } ^ { \infty } \frac { n ! } { 4 ^ { n } } ( x + 3 ) ^ { n }$ .

A) 0
B) 1
C) 2
D) 3
E) 4
F) 5
G) 6
H) $\infty$