Plant life is restricted in sea to

Options

A. Photic zone or euphotic zone
B. Aphotic zone
C. Abyssal area
D. Continental shelf

Answer

To answer the question "Plant life is restricted in sea to," we will analyze the different zones of the ocean and determine where plant life can thrive.

### Step-by-Step Solution:

1. **Understanding the Zones of the Ocean**:
- The ocean is divided into various zones based on the availability of sunlight. The main zones are the photic (or euphotic) zone, aphotic zone, abyssal zone, and continental shelf.

2. **Photic Zone (Euphotic Zone)**:
- This is the upper layer of the ocean that receives sufficient sunlight. It is essential for photosynthesis, which is the process that plants use to produce energy. Since plant life requires sunlight for photosynthesis, this zone is crucial for their survival.

3. **Aphotic Zone**:
- This zone is characterized by little to no sunlight. Since photosynthesis cannot occur in the absence of light, plant life cannot survive in this zone. Therefore, this zone is not suitable for plant life.

4. **Abyssal Zone**:
- The abyssal zone is located at great depths (around 6,600 feet to 20,000 feet) where environmental conditions are uniform, and no sunlight penetrates. As a result, plant life cannot exist here either due to the lack of light.

5. **Continental Shelf**:
- The continental shelf is a submerged area of the continent that is relatively shallow. While it can support some marine life, the depth and conditions may vary, but it is not specifically a zone where plant life is predominantly found.

6. **Conclusion**:
- Based on the analysis, the only zone where plant life is restricted to is the **photic zone (or euphotic zone)**, as it is the only area that receives enough sunlight for photosynthesis to occur.

### Answer:
**Plant life is restricted in the sea to the photic zone (euphotic zone).**

---