Correct Answer:
B. Emission of Carbon Dioxide
The correct answer is Emission of Carbon Dioxide. Burning fossil fuels (coal, oil, and natural gas) involves the combustion of hydrocarbons, which releases carbon dioxide (CO₂) as a primary byproduct. This is the main contributor to the greenhouse effect and climate change. Among the options:
- Emission of Oxygen: Incorrect; oxygen is consumed, not released, during combustion.
- Emission of Carbon Dioxide: Correct; CO₂ is the main product of fossil fuel combustion.
- Emission of Nitrogen: Incorrect; nitrogen is not a primary combustion product.
- Emission of Water Vapour: While water vapor is also produced, CO₂ is the primary concern for climate change.
Therefore, the correct answer is "Emission of Carbon Dioxide".