This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
[{'content': 'Collagen in basement membrane \nSelect and explain. \nA. Type I, B. Type II, C. Type III, D. Type IV', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Repeated question.', 'role': 'assistant'}]