This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Which of the following bones has no medullary cavity? \nSelect and explain. \nA. Ulna, B. Clavicle, C. Fibula, D. Humerus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Clavicle has no medullary cavity BD CHAURASIA S HUMAN ANATOMY Vol 1', 'role': 'assistant'}]