14.For the reaction A →products, successive half-lives are observed to be 10.0, 20.0 and 40.0 min for an experiment in which [A]0 = 0.10 M. Based on the information, the concentration of A after 30 min of the reaction is ＿ M
(A) 0.008
(B) 0.30
(C) 0.025
(D) 0.011
(E) 0.0021