This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hypolipidemic, Subject name: Pharmacology
Statins inhibit which of the following enzyme - 
Select and explain. 
A. HMG CoA reductase, B. HMG CoA synthetase, C. HMG CoA oxidase, D. Acetyl CoA synthetase
A: HMG CoA reductase
Answer: A: HMG CoA reductase 
Explanation: Ans. is 'a' i.e., HMG CoA reductase * Statins (Lovastatin) competitively inhibit the conversion of HMG-CoA to mevalonate (rate limiting step in cholesterol synthesis) by inhibiting the enzyme HMG-CoA reductase.