- The 'Raj Vayu' mobile app has been launched by a state government to provide information about the air quality index and other environmental data.
- **Option 1: Uttar Pradesh** – Known for several initiatives but not specifically linked to the 'Raj Vayu' app.
- **Option 2: Jharkhand** – Has environmental projects, though not associated with 'Raj Vayu'.
- **✅ Option 3: Rajasthan** – The correct state that launched the 'Raj Vayu' app.
- **Option 4: Uttarakhand** – Engaged in environmental monitoring but not through the 'Raj Vayu' app.
- **Option 5: Madhya Pradesh** – Has environmental initiatives but 'Raj Vayu' isn't one.

YOUR ANSWER IS RIGHT