Ocean thermal energy is due to :

Options

A. energy stored by waves in the ocean
B. temperature difference at different levels in the ocean
C. pressure difference at different levels in the ocean
D. tides arising out in the ocean

Explanation

**Step-by-step Solution:**

1. **Understanding Ocean Thermal Energy**: Ocean thermal energy refers to the energy generated from the temperature difference between the warmer surface water and the colder deep water in the ocean.

2. **Identifying the Source of Temperature Difference**: The upper layer of the ocean absorbs sunlight, making it warmer, while the deeper layers remain cold due to less sunlight penetration. This creates a temperature gradient.

3. **Heat Flow Mechanism**: The heat naturally flows from the warmer surface water to the colder deeper water due to the temperature difference. This flow of heat is what generates ocean thermal energy.

4. **Evaluating the Options**:
- **Energy stored by waves in the ocean**: This is incorrect as ocean thermal energy is not primarily due to wave energy.
- **Temperature difference at different levels in the ocean**: This is correct, as it directly relates to the concept of ocean thermal energy.
- **Pressure difference**: This is not the primary cause of ocean thermal energy.
- **Tides rising in the ocean**: This is also not related to ocean thermal energy.

5. **Conclusion**: The correct answer is that ocean thermal energy is due to the temperature difference at different levels in the ocean.

**Final Answer**: Ocean thermal energy is due to the temperature difference at different levels in the ocean.

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