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': 'The antigen lacking in Rh negative person is ? \nSelect and explain. \nA. C, B. D, C. d, D. E', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., D Rh blood group system is composed of the C, D and E antigens. D is by far the most antigenic component and the term Rh-positive means that the individual has antigen D. o Th Rh-negative individual has no D antigen.", 'role': 'assistant'}]