This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: miscellaneous, Subject name: Biochemistry
The chemical used to stop ATP synthesis is? 
Select and explain. 
A. DNSA ( di nitro salicylic acid ), B. 2,4 di nitro phenol, C. DDT, D. No chemical can stop ATP synthesis
B: 2,4 di nitro phenol
Answer: B: 2,4 di nitro phenol 
Explanation: DNSA / DNS is used for quantifying carbohydrate levels in the blood. It is mainly used in an assay of alpha-amylase. 2,4-Dinitrophenol / DNP is yellow, crystalline solid that has a sweet, musty odour & is volatile with steam. It inhibits energy (adenosine triphosphate, ATP) production in cells with mitochondria. Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colourless, tasteless, and almost odourless crystalline chemical compound, an organochlorine, originally developed as an insecticide & is a risk for hepatocellular cancer Ref: Biochemistry by U. Satyanarayana 3rd edition Pgno : 223