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: Anatomy
[{'content': 'Which of the following structure is seen in the centre of cavernous sinus? \nSelect and explain. \nA. 1st part of V nerve, B. ICA, C. 4th nerve, D. 2nd part of V nerve', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]