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: Social & Preventive Medicine
[{'content': 'Cereals are deficient in: \nSelect and explain. \nA. Tryptophan, B. Threonine, C. Lysine, D. Methionine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Lysine', 'role': 'assistant'}]