19. Which of the following statements about the series Σ (-1)"n 2 n=1 n+1 (A) The series can be shown to diverge by comparison with 00 is true? n n= (B) The series can be shown to diverge by limit comparison with (C) The series can be shown to converge by comparison with 00 n=1 n M 2 (D) The series can be shown to converge by the alternating series test. -1=