Which of the following numbers will replace the question mark (?) in the given series?
5, 6, 10, 12, 15, ?, 20, 24
A19
B18
C20
D21
A19
B18
C20
D21
Related Questions:
What should come in place of '?' in the given series based on the English alphabetical order?
MOR KMP IKN GIL ?