This section contains Assertion (A) and Reason (R) type questions. Each question has choices (1), (2), (3) and (4), out of which only one is correct.
Assertion (A) Natural gas is called clean fuel.
Reason (R) Natural gas burns without smoke.

Options

A. Both Assertion and reason are correct, and Reason is the correct explanation of Assertion.
B. Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
C. Assertion is correct, but Reason is incorrect
D. Assertion is incorrect, but Reason is correct

Answer

To solve the Assertion (A) and Reason (R) question regarding natural gas, we will analyze both statements and determine their validity.

### Step-by-Step Solution:

1. **Identify the Assertion (A)**: The assertion states that "Natural gas is called clean fuel."
- **Analysis**: This statement is true. Natural gas is often referred to as a clean fuel because it produces fewer pollutants compared to other fossil fuels like coal and oil.

2. **Identify the Reason (R)**: The reason states that "Natural gas burns without smoke."
- **Analysis**: This statement is also true. When natural gas burns, it primarily produces carbon dioxide and water vapor, and it does not produce smoke or soot, which are common byproducts of burning other fossil fuels.

3. **Evaluate the Relationship**: We need to determine if the reason supports the assertion.
- **Analysis**: The fact that natural gas burns without smoke directly supports the assertion that it is a clean fuel. The absence of smoke indicates lower emissions of harmful pollutants, which aligns with the definition of a clean fuel.

4. **Conclusion**: Both the assertion and the reason are true, and the reason correctly explains why the assertion is true.
- Therefore, the correct answer is that both the assertion and reason are correct, and the reason is a valid explanation for the assertion.

### Final Answer:
Both Assertion (A) and Reason (R) are true, and the reason supports the assertion.