They are thermoacidophiles.

a. Archaea

b. Bacteria

c. Both Archaea and Bacteria

Answer: A) Archaea

Explanation:

Thermoacidophiles are the extremophilic micro organism which comes under the condition of high temperature and the low PH value. Bacteria is the process which consist of single celled with lack of the nuclei and it is the membrane bound organelle that is why, bacteria do not included in the thermoacidophiles but it comes under in the archaea domain.