Biology

The correct answer is: A.A group of one-celled organisms with no nucleus in their cells.

Archaea are single-celled organisms that are prokaryotic, meaning they lack a nucleus and other membrane-bound organelles. Archaea are distinct from bacteria (though they are similar in being prokaryotic) and often live in extreme environments, such as hot springs or salty lakes. While archaea do not have a nucleus, they do have a unique set of characteristics that differentiate them from eubacteria, including differences in thei...