What is the correct percentage by volume of various gases in Earth's atmosphere?
           

Correct option is D

The correct percentage by volume of various gases in Earth's atmosphere is 78% nitrogen, 21% oxygen, and 0.03% carbon dioxide and other greenhouse gases.
 Oxygen is the most important chemical elements of which air is composed. It has the symbol O and has an atomic number of 8. Oxygen is a highly reactive gas that readily forms bonds known as oxides with other elements. It is also highly combustible (quick to catch fire).
 Carbon dioxide (CO2) is an important heat-trapping gas, or greenhouse gas, that comes from the extraction and burning of fossil fuels (such as coal, oil, and natural gas), from wildfires, and from natural processes like volcanic eruptions. It is a colourless and odourless gas.It is a non-flammable gas.