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: Ophthalmology
[{'content': 'The sho posterior ciliary aeries are about in number: \nSelect and explain. \nA. 10, B. 20, C. 30, D. 40', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. 20', 'role': 'assistant'}]