Which one yields more energy?

Options

A. Direct burining of cowdung
B. Burning of biogas derived from cowdung
C. Burning of manure derived from cowdung
D. Burning of semidecayed cowdung

Answer

To determine which option yields more energy, we need to analyze the energy output from different sources, specifically focusing on cow dung (gober) and its burning process.

### Step-by-Step Solution:

1. **Identify the Energy Source**: The question revolves around the energy yield from cow dung, specifically through its burning process.

2. **Understand the Burning Process**: The burning of cow dung is a direct combustion process. In this process, organic material is converted into energy through oxidation.

3. **Evaluate Energy Yield**: Direct burning of cow dung produces a significant amount of energy. This is because it releases heat energy as the organic matter combusts.

4. **Consider Methane Production**: Cow dung is also known for its ability to produce methane gas when subjected to anaerobic conditions (absence of oxygen). Methane is a potent energy source, but the question specifically asks about direct burning.

5. **Conclusion**: Based on the analysis, the direct burning of cow dung yields the highest amount of energy compared to other forms of energy extraction from cow dung.

### Final Answer:
The option that yields more energy is **direct burning of cow dung** (option number four).

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