What will come in place of the question mark (?) in the following letter series? D, E, G, J, N, ? MCQ with Answer and Explanation

Explanation:
Differences: +1,+2,+3,+4 – next +5 gives H(8)+5=13→M.

Explanation:
First letters: Z, Y, X, W, V (decreasing by 1). Second letters: A, B, C, D, E (increasing by 1). The next term is VE.

Explanation:
The series consists of letters arranged in reverse alphabetical order, with each group having three consecutive letters in reverse. QPO, NML, KJI, HGF, EDC.[reference:7]