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
The reaction which requires HMG–COA reductase activity 
Select and explain. 
A. β-hydroxy–β-methyl glutaryl COA → Mevalonic acid, B. Acetyl COA + CO2 + ATP → Malonyl COA + ADP+ Pi, C. L-methylmalonyl-CoA Succinyl COA, D. Lactose + H2O → Glucose + Galactose
A: β-hydroxy–β-methyl glutaryl COA → Mevalonic acid
Answer: A: β-hydroxy–β-methyl glutaryl COA → Mevalonic acid 
Explanation: None