Find the group of letters that best completes the analogy. Use alphabetical positions and reverse position logic where necessary. ACFL : ZXUM :: BDEM : ?

Correct — C.
Rule: letters 1 to 3 become their opposites (positions add to 27), and letter 4 moves +1.

Example: A(1)→Z(26), C(3)→X(24), F(6)→U(21), L(12)→M(13).

Apply: B(2)→Y(25), D(4)→W(23), E(5)→V(22), M(13)→N(14).

Answer: YWVN → option (c).

Why the others are wrong

• (a)
  YWNL — N in third place is wrong: E(5) pairs with V(22), since 5 + 22 = 27. The last letter L also moves M back one step instead of forward.
• (b)
  YWML — M is not the opposite of E; V is. The last letter L steps M backwards, while the example steps L forward to M.
• (d)
  YXML — X is the opposite of C, not D, whose opposite is W (4 + 23 = 27). The last two letters, M and L, miss V and N as well.

Opposite letters are pairs whose positions add to 27: A-Z, B-Y, C-X, D-W, E-V and so on. The instruction's 'reverse position logic' points to them.

The example does not use one rule throughout. A, C and F take their opposites, but L(12) becomes M(13), a +1 shift, where L's opposite would be O. Check every letter of the example before carrying a rule across.

Key facts

• Opposite pairs add to 27: B-Y, D-W, E-V, M-N.
• L is 12 and its opposite is O (15), so the example's M comes from L + 1.
• The opposite pairs in the example are A-Z, C-X and F-U.

Common traps

• Carrying a rule from the first three letters to the fourth without checking it: L's opposite is O, not M
• Pairing D with X, which is the opposite of C

No directly related past PYQ was found.