Which of the following letter-clusters will replace the question mark (?) in the given series?
AM, DK, GI, JG, ?

Given: AM, DK, GI, JG, ?

Logic: First letter increase with the place value of +3 and second letter decrease with the place value of -2
First Letter: A + 3 = D, D + 3 = G, G + 3 = J, J + 3 = M

Second Letter: M - 2 = K, K - 2 = I, I - 2 = G, G - 2 = E

So, next letter cluster is ME

Thus, the correct option  is (d).