Expression : ?, ONM, GFE, XWV The pattern followed in each letter of the terms is : 1st letter : V (-7 letters) = O (-8 letters) = G (-9 letters) = X 2nd letter : U (-7 letters) = N (-8 letters) = F (-9 letters) = W 3rd letter : T (-7 letters) = M (-8 letters) = E (-9 letters) = V Thus, missing term = VUT