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: Physiology
[{'content': 'Most commonly nerve fibre affected by pressure is: \nSelect and explain. \nA. Aa, B. AP, C. Ay, D. C', 'role': 'user'}, {'content': 'Answer: B \nExplanation: AP', 'role': 'assistant'}]