Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete?
DJ26, EK37, FL48, GM59, ?

Given: DJ26, EK37, FL48, GM59, ?

Logic: Letters are increasing + 1 and number are increasing + 11 place.

For, letter

D + 1 = E, E + 1 = F, F + 1 = G, G + 1 = H

J + 1 = K, K + 1 = L, L + 1 = M, M + 1 = N

For, number

26 + 11 = 37, 37 + 11 = 48, 48 + 11 = 59, 59 + 11 = 70

So, the missing term is HN70.

Thus, correct option is (b).