Final answer:
The main greenhouse gas responsible for global warming is Carbon Dioxide (CO2), largely produced by human activities. Although Methane also contributes, it's less abundant. Oxygen and Nitrogen don't have the same effect. The correct answer is option (B).
Step-by-step explanation:
The primary greenhouse gas responsible for trapping heat in the Earth's atmosphere and contributing to global warming is Carbon dioxide (CO2). CO2 is released into the atmosphere mainly through human activities such as burning fossil fuels (coal, oil, and natural gas), deforestation, and industrial processes.
The increase of carbon dioxide in the Earth's atmosphere creates a 'greenhouse effect', trapping heat and leading to global warming.
Methane, another potent greenhouse gas, also significantly contributes to global warming.
However, it is less abundant in the Earth's atmosphere compared to carbon dioxide. Oxygen and nitrogen, while major components of the atmosphere, are not greenhouse gases and thus do not contribute to global warming in the same way as carbon dioxide and methane.
Learn more about Greenhouse Gases