The correct option is B Nitrate
Blue Baby Syndrome is an illness that begins when large amounts of nitrates in water are ingested by an infant and converted to nitrite by the digestive system. The nitric then reacts with oxyhemoglobin to form methemoglobin, which cannot carry oxygen. If a large amount of methemoglobin is formed in the blood, body tissues may be deprived of oxygen, causing the infant to develop a blue coloration of their mucous membranes and possibly digestive and respiratory problems. This condition is also known as methemoglobinemia.