Mark the correct statement.

The major contribution in green houses is water vapour, carbon dioxide, methane, nitrous oxide, ozone, and any fluorocarbons. Global warming is because of green - house gases. Global warming is a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, CH4, and other pollutants.Ozone present in the stratosphere is good ozone and the ozone present in the troposphere is bad ozone.