• A muffler is made to lessen the noise that comes from an automobile's exhaust system. 
• The green muffler, on the other hand, is a technique for reducing noise pollution that makes extensive use of the growth of green plants around heavily inhabited areas, industrial areas, highways, etc. 
• In industrial zones, along roadsides, and in other noisy regions, four to six lines of trees are grown to achieve this. 
• In order to reduce noise pollution, the green muffler program promotes the planting of Ashoka and Neem trees nearby. 
• Additionally, noise pollution can be effectively reduced by the ground's soft surface. As a result, before cultivating plants, the ground must be prepared by adding manure.

Hence option C is the correct answer.