Select the letter-cluster from among the given options that can replace the question mark (?) in the following series. LWB → OZE→ RCH → UFK → ?

Correct — C.
Rule: +3 at every position.

First letters: L, O, R, U → U(21) + 3 = X(24).
Second letters: W, Z, C, F → F(6) + 3 = I(9).
Third letters: B, E, H, K → K(11) + 3 = N(14).

That gives XIN → option (c).

Why the others are wrong

• (a)
  CGF — CGF starts with C, but the first letters climb L, O, R, U in threes, so the next is X. Its G and F miss I and N as well.
• (b)
  BHF — BHF fails at the first letter: U + 3 is X, not B. Its H and F also miss the I and N the other columns need.
• (d)
  HIB — HIB gets the middle letter I right but starts with H instead of X and ends with B instead of N.

Treat the clusters as three columns and find each column's step. All three rise by 3 here.

The second column is the one to watch. W(23) + 3 = Z(26), then Z + 3 = 29, which wraps to C(3) because 29 − 26 = 3. A student who stops at Z thinks the column breaks. It does not: counting past Z restarts at A.

Key facts

• L = 12, O = 15, R = 18, U = 21, X = 24.
• A step past Z wraps to the start: Z(26) + 3 = 29, and 29 − 26 = 3 = C.
• Every column in this series moves +3.

Common traps

• Treating Z + 3 as a dead end instead of wrapping to C
• Checking only the middle column, where HIB also has I

No directly related past PYQ was found.