Biosphere reserves are being threatened with

Options

A. population growth
B. rains
C. pollution
D. all of these

Answer

**Step-by-Step Solution:**

1. **Understanding Biosphere Reserves:**
- Biosphere reserves are designated areas that aim to conserve biodiversity and promote sustainable development. They are ecosystems that include a variety of plants and animals in their natural habitats.

2. **Types of Conservation:**
- Biosphere reserves are a form of in-situ conservation, which means that species are conserved in their natural environment rather than in captivity.

3. **Analyzing the Threats:**
- The question asks about the threats to biosphere reserves. The options provided are population growth, rains, and pollution.

4. **Evaluating Each Option:**
- **Population Growth:** While population growth can lead to increased resource use and habitat destruction, it does not directly threaten the biosphere reserves in the same way as pollution does. Therefore, this option is not the correct answer.
- **Rains:** Increased rainfall can actually benefit biodiversity by providing more water for plants and animals. Thus, this option is also not a threat to biosphere reserves.
- **Pollution:** Pollution is a significant threat to biosphere reserves as it can degrade the environment, harm wildlife, and disrupt ecosystems. This option is the correct answer.

5. **Conclusion:**
- After evaluating all the options, the primary threat to biosphere reserves is pollution.

**Final Answer:**
Biosphere reserves are being threatened primarily by pollution.

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