Series : ANT, CPV, ERX, ?, IVB The pattern followed in each letter of the terms is : 1st letter : A (+2 letters) = C (+2 letters) = E (+2 letters) = G (+2 letters) = I 2nd letter : N (+2 letters) = P (+2 letters) = R (+2 letters) = T (+2 letters) = V 3rd letter : T (+2 letters) = V (+2 letters) = X (+2 letters) = Z (+2 letters) = B Thus, missing term = GTZ