Cambium is most active in

Options

A. (a) Pistia
B. (b) Rose
C. (c) Asparagus
D. (d) Dahlia

Answer

### Step-by-Step Solution:

1. **Understanding Cambium**: Cambium is a layer of meristematic tissue that is responsible for secondary growth in plants. It is located between the xylem and phloem.

2. **Identifying Active Seasons**: Cambium is most active during certain seasons, particularly in tropical climates where conditions are favorable for growth. This typically includes warm temperatures and adequate moisture.

3. **Analyzing the Given Options**:
- **Pistia**: A tropical plant that thrives in warm conditions, making it likely for cambium to be active.
- **Rose**: Generally grows in cooler temperatures, indicating less cambium activity.
- **Asparagus**: A temperate plant that prefers mild conditions, suggesting moderate cambium activity.
- **Dahlia**: Also a winter plant, indicating reduced cambium activity.

4. **Conclusion**: Among the options provided, **Pistia** is the only tropical plant, which means that cambium is most active in this plant during the tropical season.

5. **Final Answer**: The cambium is most active in **Pistia**.