Answer: B) Compounds contain two or more elements
Explanation:
Cyanobacteria were very simple organisms and performed were an role in changing Earth's early atmosphere. They carried out photosynthesis to produce the materials they needed to grow. In this process, they release Oxygen which is needed to sustain life on Earth for Humans and other organisms.
The third option, destroying cells
I am not sure but I am guessing carbon and nitrogen :)
The Devonian Period was part of the better known Paleozoic Period. Some scientist think it was 416 million years ago. It was the time of the great fish. It gets its name from when red rocks from Devon, England were also found in North America. It is believed that during this period parts of North America, Europe, Russia and Greenland crashed together making a new land mass. Scientists believe this period ended about 354 million years ago when land plants began to take over and much of what was an ocean disappeared.