This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory chain, Subject name: Biochemistry
Which of the following is physiological uncoupler? 
Select and explain. 
A. Thermogenin, B. 2, 4 nitrophenol, C. 2, 4 Dinitrophanal, D. Oligomycin
A: Thermogenin
Answer: A: Thermogenin 
Explanation: Physiological uncouplers i. Thyroxine, in high doses ii. Thermogenin in brown adipose tissueRef: DM Vasudevan Textbook of Medical Biochemistry, 6th edition, page no: 234