The correct answer is option-3: plantation along roadsides to reduce noise pollution.
Option-1: This option suggests that Green Muffler is a technology for reducing air pollution. However, this does not align with the given answer, which states that it is related to reducing noise pollution.
Option-2: This option states that Green Muffler is a method of afforestation. Afforestation refers to the process of establishing a forest, typically by planting trees. While afforestation can have environmental benefits, the given answer specifically mentions reducing noise pollution, not afforestation.
Option-4: This option suggests that Green Muffler is a process of reducing vibration. While reducing vibration can potentially reduce noise, the given answer specifically mentions plantation along roadsides to reduce noise pollution.
Therefore, option-3 is the best fit based on the given answer. It implies that Green Muffler refers to planting trees or vegetation alongside roads to act as a barrier and reduce the noise pollution generated by traffic.