Correct Option: B  [ Noise ]
Remark:
The Green Muffler technique is used to control noise pollution. It involves planting dense rows of trees and shrubs around roads, industrial areas, and public places. The vegetation acts as a natural sound barrier by absorbing, deflecting, and refracting sound waves, thereby reducing the intensity of noise reaching nearby areas. Common plants used for green mufflers include Neem, Ashoka, Ficus, and Cassia.
Other options (for context)
- Air pollution: Controlled by measures like emission filters and afforestation, but not directly by green mufflers.
- Soil pollution: Managed by waste treatment and reduced chemical use, not vegetation barriers.
- Water pollution: Controlled by sewage treatment and reducing industrial discharge, not by plants as mufflers.