Which of the following letter clusters will replace the blank (_____________) in the given series?
UHI, ___________ WLM, XNO, YPQ, ZRS

Correct option is C

Logic:
· First letter: +1 each step
· Second letter: +2 each step
· Third letter: +2 each step
Starting from UHI:
UHI
First letter: U
Second letter: H
Third letter: I
VJK (First letter: U+1 = V, Second letter: H+2 = J, Third letter: I+2 = K)
WLM (First letter: V+1 = W, Second letter: J+2 = L, Third letter: K+2 = M)
XNO (First letter: W+1 = X, Second letter: L+2 = N, Third letter: M+2 = O)
YPQ (First letter: X+1 = Y, Second letter: N+2 = P, Third letter: O+2 = Q)
ZRS (First letter: Y+1 = Z, Second letter: P+2 = R, Third letter: Q+2 = S)
Full series: UHI, VJK, WLM, XNO, YPQ, ZRS
Correct answer is (c) VJK