This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
[{'content': 'Ferric chloride test in PKU gives \nSelect and explain. \nA. Green, B. Red, C. Yellow, D. Blue', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Urine of the patient contains phenylketones about 500- 3000 mg/day . This could be detected by adding a drop of ferric chloride to the urine . A transient blue - green color is a positive test. But this is a less reliable test. Ref : DM.VASUDEVAN.TEXTBOOK ; SEVENTH EDITION ; PAGE NO : 237.', 'role': 'assistant'}]