What will come in place of the question mark (?) in the following letter series? KN, QT, WZ, CF, ? MCQ with Answer and Explanation

Explanation:
First letters: I, J, K, L, M (+1). Second letters: K, L, M, N, O (+1). The next term is MO.

Explanation:
First letters: A(1)+4=E(5), E+4=I(9), I+4=M(13), M+4=Q(17). Second letters: B(2)+4=F(6), F+4=J(10), J+4=N(14), N+4=R(18). The missing pair is QR.[reference:8]

Explanation:
Each letter is shifted two positions forward: D+2=F, F+2=H, H+2=J. Continuing: P+2=R, R+2=T. The missing term is PRT.[reference:2]