Answer:
Option (D).
Explanation:
Cyanobacteria (also known as blue-green algae) represent a group of bacteria which make their food by the process of photosynthesis, during which they use carbon dioxide and release oxygen.
Due to their ability to produce oxygen as a byproduct of photosynthesis, Cyanobacteria are thought to be the earliest oxygenic phototrophs that changed the early low-oxygen atmosphere (reducing atmosphere) into an oxidizing atmosphere. It led to change in Earth's living forms and evolution.
Thus, the correct answer is option (D).
