Conduction of sap in plants occurs through:

Options

A. Heart wood only
B. Sap wood only
C. Xylem as whole
D. All of these

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the conduction of sap in plants and through which part this process occurs.

2. **Identifying the Relevant Plant Structures**: In plants, there are two main types of vascular tissues involved in transport: xylem and phloem. Xylem primarily conducts water and minerals, while phloem is responsible for the transport of nutrients and sugars (sap).

3. **Focusing on Active Wood**: The term "active wood" refers specifically to the sapwood (also known as alburnum). This is the part of the xylem that is actively involved in the conduction of water and nutrients.

4. **Differentiating Between Sapwood and Heartwood**: Heartwood (or duramen) is the older, non-conducting part of the xylem that provides structural support but does not conduct sap. In contrast, sapwood is the younger, outer layer of xylem that is actively involved in sap conduction.

5. **Conclusion**: Therefore, the conduction of sap in plants occurs specifically through the **sapwood (alburnum)**.

### Final Answer:
The conduction of sap in plants occurs through **sapwood (alburnum)**.

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