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': 'All are preleukemic conditions, except: \nSelect and explain. \nA. Paroxysmal Nocturnal Hemoglobinuria, B. Paroxysmal Cold Hemoglobinuria, C. Aplastic anemia, D. Myelodysplastic syndrome', 'role': 'user'}, {'content': 'Answer: B \nExplanation: . Paroxysmal Cold Hemoglobinuria', 'role': 'assistant'}]