<prompt> Physiological uncoupler is-Thermogonin2, 4 nitrophenol2, 4DinitrophenolOligomycin  <response>: Ans. is a i.e., Thermogenin o Amongst the given options, a, b and c are uncouplers.o However, only thermogenin, among these three is a natural physiological uncoupler.i Natural:- Thermogenin, thyroxineii Synthetic:- 2,4-dinitrophenol 2,4-DNP, 2,4-dinitrocresol 2,4-DNC, and CCCP chlorocarbonylcyanidephenyl hydrazone. 