Answer: The correct answer is - Prokaryotes.
According to three domain system of classification, all life forms are grouped under three distinct domains that is- Archaea, Bacteria, and Eukarya.
Archaea and bacteria are the two different groups of prokaryotes. This classification recognises the fundamental differences between the two groups as Archaea consists of the most primitive forms of bacteria that live in harsh environmental conditions such as hotsprings.
Whereas bacteria, another group of prokaryote does not survive in the harsh conditions. There are primarily differences in the biochemical composition of these two groups.