For Which of the Following Series Will the Test for Divergence

Multiple Choice

For which of the following series will the Test for Divergence establish divergence?
1) $\sum _ { n = 1 } ^ { \infty } ( - 1 ) ^ { n }$
2) $\sum _ { n = 1 } ^ { \infty } n ^ { - 1 }$
3) $\sum _ { n = 1 } ^ { \infty } \frac { n + 1 } { 2 n }$

A) None
B) 1
C) 2
D) 3
E) 1, 2
F) 1, 3
G) 2, 3
H) 1, 2, 3