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': 'The amino acid residue having an imino side chain is: \nSelect and explain. \nA. Lysine, B. Histidine, C. Tyrosine, D. Proline', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]