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: Pharmacology
[{'content': 'The rate limiting step in the biosynthesis of cholesterol is catalyzed by: \nSelect and explain. \nA. HMG CoA lyase, B. Acetyl CoA carboxylase, C. HMG CoA reductase, D. HMG CoA synthase', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]