Given that n numbers of A.Ms are inserted between two sets of numbers a, 2b and 2a, b where a, b ∈ R. Suppose further that the mth means between these sets of numbers are same, then the ratio a : b equals
(A) n – m + 1 : m
(B) n – m + 1 : n
(C) n : n – m + 1
(D) m : n – m + 1
