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': 'Direct coombs test is positive in hemolytic anaemia due to - \nSelect and explain. \nA. Paroxysmal cold hemoglobinuria, B. Paroxysmal nocturnal hemoglobinuria, C. Hereditary spherocytosis, D. Idiopathic thrombocytopenic prpura', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]