The correct answer is D. Methane.
Gobar gas is a type of biogas that is produced by the anaerobic decomposition of animal manure. It is a renewable energy source that can be used for cooking, heating, and lighting. Gobar gas is a mixture of gases, including methane, carbon dioxide, hydrogen, and nitrogen. Methane is the main component of gobar gas, making up about 50-70% of the gas. Carbon dioxide makes up about 20-30% of the gas, and hydrogen and nitrogen make up the remaining 10-20%.
Gobar gas is a clean-burning fuel that produces fewer emissions than traditional fuels such as coal and oil. It is also a renewable resource that can be produced on a small scale, making it a good option for rural communities.
The other options are incorrect because they are not the main components of gobar gas. Carbon dioxide is a greenhouse gas that contributes to climate change. Hydrogen sulphide is a toxic gas that can cause respiratory problems.