______________is used in the production of other fuels such as producer gas and water gas.

Options

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

Answer

To solve the question, we need to identify which substance is used in the production of other fuels like producer gas and water gas. Let's break it down step by step:

### Step 1: Understand the question
The question asks for a substance that is involved in the production of other fuels, specifically producer gas and water gas.

### Step 2: Analyze the options
We have four options to consider:
1. Coke
2. Coal tar
3. Coal gas
4. Peat

### Step 3: Define each option
- **Coke**: A solid carbonaceous material produced by heating coal in the absence of air. It is used in various chemical processes, including the production of producer gas and water gas.
- **Coal tar**: A thick, black liquid produced during the carbonization of coal. It is mainly used in the production of chemicals and is not directly used to make producer gas or water gas.
- **Coal gas**: A gas produced from coal that can be used as a fuel but is not a precursor for producing other gases.
- **Peat**: An accumulation of partially decayed vegetation that can be converted into coal but is not typically used to produce producer gas or water gas.

### Step 4: Identify the correct answer
From the definitions, we see that **coke** is the only option that is used in the production of other fuels such as producer gas and water gas.

### Conclusion
Thus, the correct answer to the question is **coke**.

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