Which of them is used in extraction of metals ?

Options

A. Coke
B. Coal gas
C. Coal tar
D. Petroleum

Explanation

**Step-by-Step Solution:**

1. **Identify the Options**: The options provided are coke, coal gas, coal tar, and petroleum. We need to determine which of these is used in the extraction of metals.

2. **Understand the Source of Each Option**:
- **Coke**: This is produced by heating coal in the absence of air. It is primarily carbon.
- **Coal Gas**: This is a byproduct of the carbonization of coal and is mainly used as a fuel.
- **Coal Tar**: This is another byproduct of coal carbonization and is used in the production of chemicals, including perfumes.
- **Petroleum**: This is a liquid fossil fuel that is refined into various products but is not typically used in metal extraction.

3. **Determine the Use of Each Option**:
- **Coke**: It is widely used in the extraction of metals, particularly iron, in processes like the blast furnace.
- **Coal Gas**: Mainly used as a fuel and not in metal extraction.
- **Coal Tar**: Used for making chemicals and not in metal extraction.
- **Petroleum**: Not used in metal extraction.

4. **Conclusion**: Among the options, coke is the only substance used in the extraction of metals. It is specifically used in the reduction of iron ore (Fe2O3) to iron in a blast furnace.

5. **Final Answer**: The correct option is **coke**.

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