This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Bio-Chemistry), Subject name: Biochemistry
[{'content': 'PKU-Ferric chloride test color \nSelect and explain. \nA. Emerald green, B. Green brown, C. Purple, D. Navy blue', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (B) Green brown > A test for phenylketonuria in which ferric chloride is added to urine & turns the urine blue-green when phenylketonuria is present', 'role': 'assistant'}]