When father and mother are $R{h}^{+}$ and $R{h}^{-}$ respectively

The correct option is D First child born may be normal subsequent may suffer from erythroblastosis fetalis
When father and mother are Rh+ and Rh− respectively then the first progeny causes the release of certain Rh antigens in blood after which mother body forms antibody because it considers such antigen foreign hence first child born may be normal subsequent may suffer from erythroblastosis fetalis. So, the correct option is D. (First child born may be normal subsequent may suffer from erythroblastosis fetalis)