What is the primary function of a vehicle’s muffler?

Answer: B — To keep noise levels down

The primary function of a vehicle’s muffler is to keep noise levels down. Mufflers work by reducing the sound produced by the engine's exhaust gases as they exit the vehicle. The design of the muffler includes internal chambers and sound-absorbing materials that dissipate sound waves generated by the engine, creating a quieter operation. While other functions of a vehicle's exhaust system may contribute to fuel efficiency, engine performance, or filtration of exhaust gases, these are not the primary roles of the muffler itself. The muffler's main focus is on sound reduction, which is crucial for compliance with noise regulations and for providing a comfortable driving experience.