Which of these vehicles emission standards has been implemented throughout India since 2017 ?

Options

A. 4 wheelers: Bharat stage III , 3 wheelers : Bharat stage III , 2 wheelers : Bharat stage III
B. 4 wheelers: Bharat stage III , 3 wheelers : Bharat stage III , 2 wheelers : Bharat stage IV
C. 4 wheelers: Bharat stage III , 3 wheelers : Bharat stage III , 2 wheelers : Bharat stage III
D. 4 wheelers: Bharat stage III , 3 wheelers : Bharat stage IV , 2 wheelers : Bharat stage IV

Answer

To solve the question regarding which vehicle emission standards have been implemented throughout India since 2017, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Emission Standards**: Emission standards are regulatory limits set by governments to control the amount of pollutants that vehicles can emit. In India, these standards are known as Bharat Stage (BS) norms.

2. **Identify Bharat Stage Norms**: The Bharat Stage norms have been progressively implemented in India, starting from BS I and moving to the current standards. Each stage has stricter limits on emissions of harmful pollutants.

3. **Historical Context**: The Bharat Stage norms were introduced in 2000, with BS I being the first standard. Over the years, these standards have been updated to address environmental concerns.

4. **Focus on the Year 2017**: In 2017, the Government of India implemented Bharat Stage IV (BS IV) standards for all new vehicles. This was a significant upgrade from the previous BS III standards.

5. **Confirm the Implementation**: Since 2017, BS IV standards have been mandatory across India for all types of vehicles, including two-wheelers, three-wheelers, and four-wheelers.

6. **Conclusion**: The correct answer to the question is that Bharat Stage IV (BS IV) emission standards have been implemented throughout India since 2017.

### Final Answer:
Bharat Stage IV (BS IV) emission standards.