Identify the missing letters in the series: a, e, i, ?, o, u

C. J

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

B. H

What letter comes next in the series: b, d, f, h, ?

A. J

Identify the missing letter in the series: a, e, i, o, ?

A. U

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

B. H