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 are involved in bilirubin metabolism except? \nSelect and explain. \nA. ALA synthase, B. Heme oxygenase, C. Biliverdine reductase, D. Glucuronyl transferase', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., ALA synthase", 'role': 'assistant'}]