Concept:The related pair follows a fixed backward shift of letters in the alphabet.Explanation:In KLMN:IJKL, each letter is moved 2 places backward:K→I, L→J, M→K, N→L.Apply the same rule to TUVW:T→R, U→S, V→T, W→U.So the required term is RSTU.Answer:D. RSTU