This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
[{'content': 'Which of the following is universal donor blood group - \nSelect and explain. \nA. A, B. B, C. AB, D. O', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Individuals with type O Rh D negative blood are often called universal donors, as they do not contain antigen A and B on the surface of their RBC and those with type AB Rh D positive blood are called universal recipients ref:harsh mohan text book pathology', 'role': 'assistant'}]