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
Statins are given at night because ? 
Select and explain. 
A. HMG-CoA reductase activity is maximum in midnight, B. Statins are maximally absorbed in night, C. Statins have more potency in night, D. Convenient for patient to remember
A: HMG-CoA reductase activity is maximum in midnight
Answer: A: HMG-CoA reductase activity is maximum in midnight 
Explanation: Ans. is'a' i.e., HMG-CoA reductase actiyity is maximum in midnight(Ref: KDT 7/e p.637; Clinical pharmacology 3d/ep.939)Because HMG-CoA reductase activity is maximum at midnight, all statins are administered at bed time to obtain maximum effectiveness.However, this is not necessary for atorvastatin and rosuvastatin, which have long plasma t 1/2.