This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Antigen absent in Bombay blood group- \nSelect and explain. \nA. H, B. A, C. B, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. is \'a\' i.e., H; \'b\' i.e., A & \'c\' i.e., B"Bhende et al (1952) from Bombay repoed the very rare instatnce in which A and B antigens as well as the H antigens are absent from red cells. This is known as Bombay or OH blood"', 'role': 'assistant'}]