LKJ : pon :: ? : hgf

dcle
DBC
dcd
DCB

The answer is D. DCB.

The first letter of each pair of words is three places forward in the alphabet.

LKJ : pon :: DCB : hgf

L is three places forward from P, so D is three places forward from H.

K is three places forward from O, so C is three places forward from G.

J is three places forward from N, so B is three places forward from F.