There is a higher propensity for gastric ulcers in people in the type _O_ blood group because an H. pylori lectin binds an oligosaccharide in the glycoproteins and glycolipids of that blood group.
This is because an H. pylori lectin binds an oligosaccharide in the glycoproteins and glycolipids of blood type Other than blood types AB or B.
Answer is D. Because the chemoreceptors located in the carotid and aortic bodies monitor the concentration of carbon dioxide and oxygen in the arterial blood.