The blue baby syndrome results from

The correct option is D Methaemoglobin
Blue baby syndrome occurs commonly when newborn babies have cyanotic heart defects. It is also called as methemoglobinemia. It is characterized by reduced ability of the blood to carry oxygen because of reduced levels of normal haemoglobin. Infants are most often affected and may seem healthy but show signs of blueness around the mouth, hands, and feet, hence the common name blue baby syndrome. These children may also have trouble breathing as well as vomiting and diarrhoea.

Thus, the correct answer is option D.