What is the function of a muffler in a vehicle?

The primary function of a muffler in a vehicle is to reduce noise from the exhaust system. As exhaust gases exit the engine, they can create significant noise due to the rapid expansion and turbulence of these gases. The muffler employs various internal structures, such as chambers and perforated tubes, to dissipate sound waves and diminish the volume of the noise entering and exiting the vehicle. This function ensures a quieter ride and compliance with noise regulations.

While options like reducing engine power, increasing fuel efficiency, and improving acceleration can be influenced by other components of the exhaust system, they are not the primary role of the muffler. Instead, its main purpose is sound attenuation, making option C the correct answer.