BCB, DED, FGF, HIH, ___\nOptions:\n(A) KOP\n(B) QLM\n(C) JKJ\n(D) PSQ\n(E) IOP
A step-by-step solution is:
(C)
This series consists of a simple alphabetical order with the first two letters of all segments: B, C, D, E, F, G, H, I, J, K.

The third letter of each segment is a repetition of the first letter.

.

The final answer: (C)