Cryopreservation is:

Options

A. Preservation of living beings in chemicals
B. preservation through gases
C. preservation at very low temperature
D. Preservation at high temperature

Answer

### Step-by-Step Solution:

1. **Understanding Cryopreservation**:
- Cryopreservation refers to the process of preserving cells, tissues, or any biological constructs by cooling them to very low temperatures. This process is used to maintain the viability of the biological material for future use.

2. **Evaluating the Options**:
- **Option 1**: "Preservation of living beings in chemicals" - This is incorrect because cryopreservation does not specifically involve chemicals for preservation but rather focuses on low temperatures.
- **Option 2**: "Preservation through gases" - This is also incorrect as cryopreservation does not involve using gases for preservation.
- **Option 3**: "Preservation at very low temperature" - This is correct. Cryopreservation typically involves storing biological materials at temperatures around -196°C using liquid nitrogen.
- **Option 4**: "Preservation at high temperature" - This is incorrect because high temperatures generally lead to the degradation of biological materials.

3. **Justifying the Correct Option**:
- The correct option, which is option 3, aligns with the definition of cryopreservation. It emphasizes the significance of low temperatures in reducing metabolic activity and preventing cellular damage, thus preserving the biological material effectively.

4. **Conclusion**:
- Therefore, the best description of cryopreservation is "preservation at very low temperature," making option 3 the correct answer.