The verified answer to “In a certain code, WALL is written as UYJJ. How will BIRD be written in that code?” is ZGPB, option C. The source working states: Correct answer: ZGPB (Option D). Apply the same unchanged rule to BIRD: B→Z, I→G, R→P, D→B. Therefore the required code is ZGPB. Wrong options: CJSE is wrong because it does not reproduce the verified rule at every position; DKTF is wrong because it does not reproduce the verified rule at every position; AHQC 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 ZGPB. The alternatives DKTF, AHQC and CJSE fail because at least one position does not obey the same transformation. A useful final check is to map ZGPB backward through the inverse operation and confirm that the original target is recovered.