Thermal algae survive at

Options

A. Low temperature
B. Hot water of `30^(@)-40^(@)C`
C. Hot spring at `70^(@)C`
D. Frozen lakes and ocean.

Answer

**Step-by-Step Solution:**

1. **Understanding Thermal Algae**: The question refers to "thermal algae," which are more accurately known as "thermophilic algae." These algae thrive in high-temperature environments.

2. **Identifying Temperature Ranges**: Thermophilic algae typically grow in environments with temperatures ranging from 60 to 70 degrees Celsius. This is significantly higher than the temperatures found in most aquatic environments.

3. **Analyzing the Options**:
- **Low Temperature**: This option is incorrect because thermophilic algae require high temperatures, not low ones.
- **Hot Water of 30 to 40 Degrees Celsius**: This option is also incorrect. While this is warm water, it does not reach the high temperatures that thermophilic algae need.
- **Hot Spring at 70 Degrees Celsius**: This option is correct. Hot springs can reach temperatures that are suitable for thermophilic algae, making this the best choice.
- **Frozen Lakes and Oceans**: This option is incorrect as it refers to low temperatures, which are unsuitable for thermal algae.

4. **Conclusion**: The correct answer is that thermal algae survive in hot springs at 70 degrees Celsius.

**Final Answer**: Hot spring at 70 degrees centigrade.

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