The correct option is A Chemoorganotrophs
A chemoorganotroph is an organism, that obtains energy from the oxidation of reduced organic compounds. The list of compounds from which chemoorganotrophic organisms can generate energy and their sources of carbon is very long, making these microorganisms extremely versatile. Two mechanisms for energy conservation are known for chemoorganotrophs: fermentation and respiration.
So answer is - 'Chemoorganotrophs'.