Identify the missing number in the series: 3, 7, 15, 31, ?, 127

A. 63

M, O, Q, S, ?

B. T

Identify the missing letter in the series: Z, Y, X, W, ?

A. V

What letter should come next in the series: z, x, v, t, ?

C. U

Complete the series: m, o, q, s, ?

A. T