What will come in place of the question mark (?) in the following letter series? ACE, BDF, CEG, DFH, ___ MCQ with Answer and Explanation

Explanation:
The second and fourth letters (K and L) are static. The first and third letters are in alphabetical order starting with C. So, the missing letters are IKJL.[reference:11]

Explanation:
First: M, S, Y, E, K (+6 each, wrap). Second: P, V, B, H, N (+6 each, wrap). So KN.

Explanation:
U(21)+3=X(24), X+5=C(29→3), C+7=J(10), J+9=19→S. So S.