Answer:
The correct answer is option - chemoautotrophs.
Explanation:
Chemoautotrophs are one of the chemotrophic organisms that obtain their energy by chemosynthesis instead of photosynthesis or oxidation of electron donors present in their environment. Such organisms are bacteria or protozoans generally and the molecules from they get their energy can be organic or inorganic molecules.
Thiobacillus ferroxidans is also an example of chemoautotrophic organisms.
Thus, the correct answer is option A. chemoautotrophs.
