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: Biochemistry
[{'content': 'Which of the following does not contain keratin \nSelect and explain. \nA. Potato, B. Tomato, C. Carrot, D. Spinach', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Potato', 'role': 'assistant'}]