Most of the fuels are

Options

A. carbon compounds with sulphur
B. nitrogen compounds with carbon
C. carbon compounds with hydrogen
D. none of these

Answer

**Step-by-Step Solution:**

1. **Understanding Fuels**:
- Fuels are substances that can release energy when they undergo a chemical reaction, typically combustion.

2. **Identifying Common Characteristics of Fuels**:
- Most fuels are made up of organic compounds. The most common type of organic compounds found in fuels are hydrocarbons.

3. **Defining Hydrocarbons**:
- Hydrocarbons are organic compounds that consist solely of carbon (C) and hydrogen (H) atoms. They can be found in various forms such as gases (like methane), liquids (like gasoline), and solids (like coal).

4. **Analyzing the Options**:
- Option 1: Carbon compounds with sulfur - While some fuels may contain sulfur, it is not a defining characteristic of most fuels.
- Option 2: Nitrogen compounds with carbon - This is not a common characteristic of fuels.
- Option 3: Carbon compounds with hydrogen - This accurately describes hydrocarbons, which are the primary constituents of most fuels.
- Option 4: None of these - This option is incorrect as we have identified hydrocarbons as fuels.

5. **Conclusion**:
- Based on the analysis, the correct answer is **Option 3: Carbon compounds with hydrogen**.

---