For a given value of degree of dissociation, which of the following have correct Van't Hoff factor?

The expression to determine van't Hoff factor of a solution is given by:i=1+(n−1)αn= number of ions formed after dissociationα= Degree of dissociationwhere, i= van't Hoff factorA. For NaCl; n=2 so i=1+α B. For Ca(NO3​)2​; n=3 so i=1+2αC. For K4​[Fe(CN)6​];  n=5 so i=1+4αD. For (NH4​)3​PO4​; n=4 so i=1+3α