Which of the following statements gives a sufficient set of conditions for the alternating series ∑n=1∞(−1)nan to converge?
a) {an} is positive and bounded above by 1.
b) {an} is eventually decreasing, but the limit of an need not be 0.
c) {an} is eventually decreasing and n→∞liman=0.
d) n→∞liman=0.