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

B. H

What letter completes the series: z, x, v, t, ?

C. Q

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

C. Q

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

B. H

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

A. R