Answer: The correct answer is -
Archaea.
Step-by-step explanation:
Archaea is one three domains of life forms (according to Carl Woese three domain system of classification) that includes prokaryotic organisms that survive under extremely harsh environmental conditions such as hotsprings, volcanic eruption, highly acidic conditions etc.
These organsisms are therefore also known as extremophiles.
Example - Methanogens.
Thus, Archaea is the right answer.