Which one of the following is a renewable source of energy?

Options

A. Petroleum
B. Coal
C. Nuclear fuel
D. Trees.

Answer

### Step-by-Step Solution:

1. **Understanding Renewable Energy**:
- Renewable energy sources are those that can be replenished naturally over time. They are sustainable and can be used repeatedly without depleting the resource.

2. **Analyzing the Options**:
- **Option A: Petroleum**:
- Petroleum is derived from fossil fuels and takes millions of years to form. It is extracted from the earth and cannot be replenished in a human timeframe. Therefore, it is a non-renewable resource.
- **Option B: Coal**:
- Coal is also a fossil fuel formed from ancient organic matter. Like petroleum, it cannot be regenerated quickly and is classified as a non-renewable resource.
- **Option C: Nuclear Fuel**:
- Nuclear fuel, primarily derived from uranium, is mined and used for energy production. The process of forming uranium takes a long time, and it cannot be regenerated quickly, making it a non-renewable resource.
- **Option D: Trees**:
- Trees can be planted and grown again. They can be harvested sustainably if managed properly, making them a renewable resource.

3. **Identifying the Correct Answer**:
- After evaluating all options, the only renewable source of energy among the given choices is **Option D: Trees**.

### Final Answer:
The renewable source of energy is **Option D: Trees**.

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