Combustion of fossil fuels most directly affects the

Options

A. carbon cycle.
B. water cycle.
C. nitrogen cycle
D. phosphorus cycle.

Answer

**Step-by-Step Solution:**

1. **Understanding Fossil Fuels**: Fossil fuels such as coal, petrol, and diesel are natural resources that are formed from the remains of ancient plants and animals. Their combustion refers to the process of burning these fuels to release energy.

2. **Combustion Process**: When fossil fuels are burned, they release various gases into the atmosphere. The primary gases released include carbon dioxide (CO2), carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2).

3. **Impact on Carbon Cycle**: The combustion of fossil fuels significantly increases the amount of carbon dioxide in the atmosphere. This excess carbon dioxide disrupts the natural carbon cycle, which is the process by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere.

4. **Consequences of Disruption**: The increase in carbon dioxide levels leads to pollution and contributes to climate change. This is because carbon dioxide is a greenhouse gas that traps heat in the atmosphere, leading to global warming.

5. **Conclusion**: Therefore, the combustion of fossil fuels most directly affects the carbon cycle, as it alters the balance of carbon in the environment and contributes to environmental issues such as climate change.

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