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': 'All the following are sulphur containing amino acids found in proteins except \nSelect and explain. \nA. Cysteine, B. Cystine, C. Methionine, D. Threonine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Sulfur-containing amino acids: Cysteine, Methionine.\nReference: Vasudevan 7th\xa0 ed, pg 24', 'role': 'assistant'}]