Plant cooling occurs due to

Options

A. Assimilation
B. Guttation
C. Photorespiration
D. Transpiration

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the process responsible for cooling in plants.

2. **Identifying the Options**: The options given are:
- Assimilation
- Guttation
- Photorespiration
- Transpiration

3. **Analyzing Each Option**:
- **Assimilation**: This refers to the process by which plants use minerals and nutrients to build their own tissues. It does not involve any cooling effect.
- **Guttation**: This is the process where water is exuded from the leaves in liquid form, usually at night. It does not contribute to cooling.
- **Photorespiration**: This is a process that occurs when the concentration of oxygen is high and can interfere with photosynthesis. It does not provide a cooling effect.
- **Transpiration**: This is the process of water evaporation from the plant's surface, primarily through stomata on the leaves. During transpiration, water is lost in vapor form, which helps cool the plant, similar to how sweating cools the human body.

4. **Conclusion**: Based on the analysis, the correct answer is **Transpiration**. This process is crucial for cooling plants during high temperatures.

### Final Answer:
Plant cooling occurs due to **Transpiration**.