In the sequence: A1, B2, C3, ?, E5, what should replace the question mark?

A. D4

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

A. E

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

A. 16

In the series X, Y, Z, ?, B, C, what character should replace the question mark?

A. A

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

A. D