The verified answer to “In a certain code, SOUND is written as EOVPT. How will CAT be written in that code?” is UBD, option C. The source working states: Correct answer: UBD (Option D). Apply the same unchanged rule to CAT: C→U, A→B, T→D. Therefore the required code is UBD. Wrong options: DBU is wrong because it does not reproduce the verified rule at every position; ECV is wrong because it does not reproduce the verified rule at every position; BZS 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 UBD. The alternatives ECV, BZS and DBU fail because at least one position does not obey the same transformation. A useful final check is to map UBD backward through the inverse operation and confirm that the original target is recovered.