The gas responsible for global warming is
Carbon monoxide
Carbon dioxide
Nitrogen dioxide
Sulphur dioxide

Correct answer: (b) Carbon dioxide

Explanation: The gas responsible for global warming is Carbon dioxide. The greenhouse effect, a warming of Earth's surface and troposphere (the lowest layer of the atmosphere) caused by the presence of water vapour, carbon dioxide, methane, and certain other gases in the air. This causes a rise in temperature leading to global warming.