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': 'The deficiency of coagulation factor IX is associated with: \nSelect and explain. \nA. Haemophilia A, B. Haemophilia B, C. Henoch-schonlein purpura, D. Sickle cell anaemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Genetic conditions dealt with by clinicians in other specialties:', 'role': 'assistant'}]