Answer:
By far, the most abundant gas in the Earth's atmosphere is nitrogen, which accounts for about 78% of the mass of dry air.
Explanation:
The correct option is A.
Living organisms depend on their environment to survive, when there are changes in the environment which are not favorable to the living organisms, it will eventually leads to the wiping out of the living organisms. As time goes on and the environment recover, the living organisms that will be found in the new environment are those who will be able to survive in it.
