Question

15. These photosynthetic organisms can live in extreme environments, sometimes harnessing energy from chemicals, and are among some of the oldest organisms on Earth.
Οalgae
O protists
O cyanobacteria
O diatoms

Answer 1

Answer:

cyanobacteria

Explanation:

the answer of this question the 3rd one, because if you were to think and look up the oldest Bactria it would be that answer.