Answer: b. Archaeabacteria
Pyrolobus fumarii is the species of archeabacteria. These organisms are known for their ability to survive in the extreme high temperatures. They are called as hyperthermophiles. They are found in the deep sea vent, and beneath the earth crust. The cells of these organisms are circular. They have lobed shaped cocci cells. These organisms are used in processing of agricultural products, animal feeding and other human consumable products.