Carbon dioxide is liberated during

Options

A. Photosynthesis
B. Respiration
C. Transpiration
D. Ascent of sap.

Answer

**Step-by-Step Solution:**

1. **Understanding the Processes**: First, we need to understand the four processes mentioned in the question: photosynthesis, respiration, transpiration, and ascent of sap.

2. **Analyzing Each Process**:
- **Photosynthesis**: This is the process by which green plants convert light energy into chemical energy, using carbon dioxide and water, and releasing oxygen. Carbon dioxide is not liberated; instead, it is consumed.
- **Respiration**: This is the process where organic substances (usually glucose) are broken down with the use of oxygen to release energy. During this process, carbon dioxide and water are produced as byproducts.
- **Transpiration**: This is the process of water loss from plants, mainly through the leaves. It does not involve the release of carbon dioxide.
- **Ascent of Sap**: This refers to the movement of water and nutrients from the roots to the leaves in plants. It does not involve the release of carbon dioxide.

3. **Identifying the Correct Process**: From the analysis, it is clear that respiration is the only process among the options that liberates carbon dioxide.

4. **Conclusion**: Therefore, the correct answer to the question "Carbon dioxide is liberated during" is **respiration**.

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