In each of the following questions, the second group of letters is formed from the first using a specific alphabetical transformation. Apply the same pattern to the third group and find the correct option that completes the analogy. QDXM : SFYN :: UIOZ : ?

Correct — D.
Rule: +2, +2, +1, +1 on the four letters in turn.

Q(17) → S(19): +2
D(4) → F(6): +2
X(24) → Y(25): +1
M(13) → N(14): +1

U(21) + 2 = W, I(9) + 2 = K
O(15) + 1 = P, Z(26) + 1 wraps to A

WKPA → option (d).

Why the others are wrong

• (a)
  PAQM — PAQM fails from the first letter: U + 2 is W, not P. None of its four letters matches the +2, +2, +1, +1 shift.
• (b)
  LPWA — LPWA ends correctly in A, since Z + 1 wraps to A, but its first three letters fail: U + 2 is W, not L.
• (c)
  QNLA — QNLA also ends in A, but U + 2 is W, not Q, and I + 2 is K, not N. The shift breaks at the first letter.

A letter-group analogy maps each letter of the first group to the letter in the same place in the second. Write each letter's alphabet position and read the four differences.

The differences need not be equal: here they run +2, +2, +1, +1. Apply them in the same order to UIOZ, and count past Z back to A when a shift runs off the end.

Key facts

• Positions used here: D4, I9, M13, O15, Q17, U21, X24, Z26.
• The alphabet wraps round: Z + 1 = A, and Y + 3 = B.
• Each place in the group keeps its own shift, so +2, +2, +1, +1 is applied letter by letter, in order.

Common traps

• Stopping at Z because 27 is not a letter, instead of wrapping round to A
• Using one shift for all four letters after checking only the first pair

No directly related past PYQ was found.