What is the primary function of the exhaust muffler baffle inside a motorcycle's silencer assembly?

1. To reduce the noise level of the exhaust gases by forcing them through a series of chambers and perforated tubes, and to provide necessary exhaust backpressure.
2. To filter out harmful carbon monoxide gases and turn them into carbon dioxide.
3. To prevent engine oil from blowing out of the exhaust pipe.
4. To increase the engine sound level to make the motorcycle more visible.