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: Medicine
[{'content': 'A stem cell disorder affecting all the three cell lines; platelets, RBCs and leucocytes is - \nSelect and explain. \nA. Hemolytic anaemia, B. Paroxysmal cold haemoglobinuria, C. Paroxysmal nocturnal haemoglobinuria, D. Blackfan Diamond syndrome', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]