Select the letter-cluster from among the given options that can replace the question mark (?) in the following series. MIN, NJM, OKL, PLK, ?

Correct — C.
Rule: first and second letters +1, third letter −1.

First letters: M, N, O, P → Q.
Second letters: I, J, K, L → M.
Third letters: N, M, L, K → J.

That gives QMJ → option (c).

Why the others are wrong

• (a)
  QWS — QWS has the right first letter but jumps the second from L to W. The second letters step +1, I, J, K, L, so the next is M.
• (b)
  HGF — HGF breaks at the first letter. M, N, O, P climb by one, so the next first letter is Q, not H.
• (d)
  UJH — UJH starts with U, five places after P instead of one. The first letters climb +1 to Q, and the third letter should be J, not H.

Read a letter-cluster series down each position, not across each cluster. Each position can carry its own step, and the steps need not run in the same direction.

Here the first and second letters climb by one while the third falls by one. Track each column on its own and the answer builds itself: Q, M, J. The first letter alone already narrows the options to QWS and QMJ.

Key facts

• Each position in a letter-cluster series can follow its own rule.
• Here positions one and two step +1 and position three steps −1.
• N(14), M(13), L(12), K(11), J(10) is a −1 run.

Common traps

• Assuming all three letters move in the same direction
• Stopping at the first letter when two options start with Q

No directly related past PYQ was found.