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': 'Least irritant fluid to peritoneum - \nSelect and explain. \nA. Blood, B. Urine, C. Bile, D. Pancreatic fluid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]