Assertion : CNG and LPG are clean fuels.
Reason : They do not leave any residue on burning.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

To analyze the assertion and reason provided in the question, we can break it down into clear steps:

### Step 1: Understand the Assertion
The assertion states that CNG (Compressed Natural Gas) and LPG (Liquefied Petroleum Gas) are clean fuels.

**Hint:** A clean fuel is one that produces minimal pollutants when burned.

### Step 2: Understand the Reason
The reason given is that CNG and LPG do not leave any residue when they are burned.

**Hint:** Residue refers to any leftover material after combustion, such as soot or ash.

### Step 3: Analyze the Relationship
Now, we need to determine if the reason supports the assertion. If CNG and LPG do not leave any residue upon burning, it implies that they are indeed cleaner options compared to other fuels that may leave behind soot or other pollutants.

**Hint:** Consider how the absence of residue can relate to the overall cleanliness of a fuel.

### Step 4: Conclusion
Since the reason directly supports the assertion that CNG and LPG are clean fuels, we can conclude that both the assertion and the reason are true, and the reason correctly explains why the assertion is true.

**Hint:** Look for logical connections between statements to determine their validity.

### Final Answer
Both the assertion and the reason are true, and the reason correctly explains the assertion.

### Summary
- **Assertion:** CNG and LPG are clean fuels.
- **Reason:** They do not leave any residue on burning.
- **Conclusion:** Both are true and the reason supports the assertion.