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': 'Rich source of IgG is: \nSelect and explain. \nA. Stomach, B. Visceral peritoneum, C. Small intestine, D. Large intestine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Small intestine (Most probably) Most abundant immunoglobin in blood --> IgG.', 'role': 'assistant'}]