The verified answer to “In a certain code, NEST is written as ENTS. The source working states: Correct answer: OHSUE (Option B). Apply the same unchanged rule to HOUSE: H→O, O→H, U→S, S→U, E→E. Therefore the required code is OHSUE. Wrong options: IPVTF is wrong because it does not reproduce the verified rule at every position; JQWUG is wrong because it does not reproduce the verified rule at every position; GNTRD is wrong because it does not reproduce the verified rule at every position. Even one mismatched position invalidates a code, so only Option B 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 OHSUE. The alternatives JQWUG, GNTRD and IPVTF fail because at least one position does not obey the same transformation. A useful final check is to map OHSUE backward through the inverse operation and confirm that the original target is recovered.