Choose the missing terms out of the given alternatives : UPI, ?, ODP, MBQ, IAW

Answer: Option B

1st letter : U - 2 = S - 4 = O - 2 = M - 4 = I
2nd letter : P - 8 = H - 4 = D - 2 = B - 1 = A
3rd letter : I + 1 = J + 6 = P + 1 = Q + 6 = W