The verified answer to “In a certain code, WORLD is written as EMSPX. How will APPLE be written in that code?” is FMQQB, option C. The source working states: Correct answer: FMQQB (Option D). Apply the same unchanged rule to APPLE: A→F, P→M, P→Q, L→Q, E→B. Therefore the required code is FMQQB. Wrong options: BQQMF is wrong because it does not reproduce the verified rule at every position; CRRNG is wrong because it does not reproduce the verified rule at every position; ZOOKD is wrong because it does not reproduce the verified rule at every position. Even one mismatched position invalidates a code, so only Option D is correct. This observation must be confirmed across every available letter position or every consecutive term before it is applied to the missing code. Applying the verified rule to the target expression produces FMQQB. The alternatives CRRNG, ZOOKD and BQQMF fail because at least one position does not obey the same transformation. A useful final check is to map FMQQB backward through the inverse operation and confirm that the original target is recovered.