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

A. E

In a series of letters: D, F, H, J, ?, P. What is the missing letter?

A. K

Identify the missing character in the series: 2, 4, 6, ?, 10. What number should replace the question mark?

B. 8

Identify the missing character in the series 1, 4, 9, ?, 25.

A. 16

What character should replace the question mark in the sequence A, B, C, ?, E?

A. D