Correct Answer: Carbon dioxide

Solution : The correct answer is (A) Carbon dioxide

Carbon dioxide (CO2) is the primary greenhouse gas responsible for global warming. It is released into the atmosphere through various human activities, such as the burning of fossil fuels (coal, oil, and natural gas), deforestation, and industrial processes. CO2 is a long-lived greenhouse gas that can remain in the atmosphere for extended periods.

The increase in carbon dioxide concentrations in the atmosphere is a significant driver of climate change. It acts as a heat-trapping gas, allowing sunlight to enter the Earth's atmosphere but trapping the outgoing heat radiation, resulting in a warming effect known as the greenhouse effect. This leads to an increase in global temperatures and contributes to climate change.

While other greenhouse gases such as methane (CH4), nitrous oxide (N2O), and ozone (O3) also contribute to global warming, carbon dioxide is the most abundant and persistent greenhouse gas, making it the primary driver of long-term climate change. Reducing carbon dioxide emissions and finding sustainable alternatives to fossil fuel use are essential steps in mitigating global warming and addressing climate change.