Which of the following is an ecosystem service provided by a natural ecosystem?

Options

A. Cycling of nutrients
B. prevention of soil erosion
C. Pollutant absorption and reduction of the threat of global warming
D. All of the above

Explanation

To determine which of the following is an ecosystem service provided by a natural ecosystem, we need to analyze each option given in the question.

### Step-by-Step Solution:

1. **Understanding Ecosystem Services**:
- Ecosystem services are the benefits that humans derive from natural ecosystems. They include processes such as nutrient cycling, soil formation, and pollution absorption.

2. **Evaluating Each Option**:
- **Option A: Cycling of Nutrients**:
- This is indeed an ecosystem service. Healthy ecosystems recycle nutrients, which are essential for plant growth and maintaining soil fertility.
- **Option B: Prevention of Soil Erosion**:
- This is also an ecosystem service. Natural ecosystems, especially those with vegetation, help to prevent soil erosion by stabilizing the soil with roots and reducing the impact of rainfall.
- **Option C: Pollutant Absorption and Reduction of the Threat of Global Warming**:
- This is another ecosystem service. Ecosystems can absorb pollutants and act as carbon sinks, helping to mitigate climate change by storing carbon dioxide.
- **Option D: All of the Above**:
- Since all the previous options are valid ecosystem services provided by natural ecosystems, this option is correct.

3. **Conclusion**:
- After analyzing all the options, we conclude that all of them represent ecosystem services. Therefore, the correct answer is **Option D: All of the Above**.

### Final Answer:
**Option D: All of the Above**

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