SSC CHSL 7 Mar 2018 Shift 1 Paper

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