In the sequence A, B, C, D, ?, F, G, what character should replace the question mark?

A. E

What character should be inserted in the sequence X, Y, ?, A, B, C?

A. Z

In a sequence of letters: A, C, E, G, ?, K, M, O, what is the missing letter?

B. H

What character should replace the question mark in the pattern X, Y, Z, A, B, ?

A. C

In a sequence of letters: A, C, E, G, ?, K. What is the missing letter?

C. H