Transpiration is

Options

A. absorption of water by roots
B. transportation of water by xylem
C. transportation of minerals by phloem
D. evaporation of water by leaves

Explanation

**Step-by-Step Solution:**

1. **Understanding Transpiration**:
Transpiration is a biological process that involves the movement of water within a plant and its evaporation from aerial parts, primarily the leaves.

2. **Identifying Aerial Parts**:
The aerial parts of a plant include the leaves, stems, and fruits. These are the parts that are above the ground and are responsible for transpiration.

3. **Defining Evaporation**:
Evaporation is the process by which water changes from a liquid state to a gaseous state. In the context of plants, this occurs when water is lost from the surface of the leaves into the atmosphere.

4. **Role of Stomata**:
The evaporation of water during transpiration primarily occurs through small openings on the leaves called stomata. These stomata allow water vapor to exit the leaf while also facilitating gas exchange for photosynthesis.

5. **Conclusion**:
Therefore, transpiration can be defined as the evaporation of water from the aerial parts of a plant, especially through the leaves.

**Final Answer**: Transpiration is the evaporation of water by leaves.

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