What letter comes next in the series: A, E, I, M, ?

A. O

Find the odd one out in the series: A, C, E, G, I, K, M, O, Q, R

D. R

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

B. H

Complete the series: x, u, r, o, ?

A. L

Find the missing letters in the series: b, d, f, h, ?

A. J