If the sequence is A, C, E, G, what letter comes next?

A. I

In the series 2, 4, 8, 16, what is the next number?

B. 32

Which of the following does not belong in the series: 3, 6, 9, 12, 15, 18, 20?

D. 20

Identify the pattern: 5, 10, 20, 40, ?

C. 80

If 'A' is to 'Z', 'B' is to 'Y', and 'C' is to 'X', what is 'D' to?

A. W