One of the following is not a possible reason for use of CNG in automobiles:

Options

A. It can be adulterated
B. It is cheaper than petrol
C. It burns more efficiently
D. It reduce pollution.

Answer

To determine which option is not a possible reason for the use of CNG (Compressed Natural Gas) in automobiles, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understand the Context of CNG**:
- CNG is used as an alternative fuel for vehicles. It is known for its cost-effectiveness, efficiency, and lower pollution levels compared to traditional fuels like petrol.

2. **Analyze Each Option**:
- **Option 1: It can be adulterated**:
- Adulteration refers to the addition of impurities to a substance. CNG is a clean fuel and is not typically adulterated. Therefore, this statement does not support the use of CNG in automobiles.
- **Option 2: It is cheaper than petrol**:
- CNG is indeed cheaper than petrol, making it a financially attractive option for consumers. This is a valid reason for its use.
- **Option 3: It burns more efficiently**:
- CNG burns more efficiently than petrol, which means it provides more energy per unit of fuel consumed. This is another valid reason for its use.
- **Option 4: It reduces pollution**:
- CNG produces fewer emissions compared to petrol, contributing to reduced air pollution. This is a significant reason for its adoption in vehicles.

3. **Identify the Incorrect Option**:
- After analyzing all options, the statement "It can be adulterated" is the only option that does not represent a valid reason for the use of CNG in automobiles.

4. **Conclusion**:
- The answer to the question is that "It can be adulterated" is not a possible reason for the use of CNG in automobiles.

### Final Answer:
The option that is not a possible reason for the use of CNG in automobiles is: **It can be adulterated**.