Archaea Are

Archaea are

A) primarily ancient organisms that have not evolved very much in the last billion years.
B) phylogenetically diverse, but functionally restricted to extremophiles and chemolithotrophs.
C) a group of diverse microorganisms that inhabit almost every environment on Earth, including the colon of humans and other mammals.
D) functionally diverse, but restricted to thermophilic or hyperthermophilic environments.