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': 'In cholesterol synthesis, which is rate limiting amino acid: \nSelect and explain. \nA. HMG CoA reductase, B. HMG CoA synthetase, C. 7 alpha hydroxylase, D. Phosphofructokinase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. HMG COA reductase', 'role': 'assistant'}]