Find the missing letter in the series: z, x, v, t, ?

A. R

Identify the missing letter in the series: Z, X, V, T, ?

B. S

What is the next letter in the series: A, C, E, G, ?

B. H

Complete the series: a, c, e, g, ?

B. H

Find the missing letter in the series: z, x, v, t, ?

A. R