Three of the following four letter-clusters are alike in a certain way and one is different. Pick the odd one out.

Correct option is C

In this question following logic is followed-
1^st letter + 3 = 2^nd letter and 3^rd letter is opposite letter of the 1^st letter.
Option (a) EHV = E → (+3) = H and E ⇆ V
Option (b) BEY = B → (+3) = E and B ⇆ Y
Option (c) JMP = J → (+3) = M and J ⇆ Q ≠P
Option (d) GJT = G → (+3) = J and G ⇆ T
Therefore, the correct answer is (c).