You are driving a motor vehicle with a manual gearbox. When driving, what can cause avoidable noise pollution?

The combination of options 1, 2, and 3 addresses various actions and conditions that contribute to avoidable noise pollution when driving a motor vehicle.

1. Heavily accelerating unnecessarily creates excessive engine noise and can disturb other road users, which is generally discouraged under German traffic regulations concerning noise pollution.
2. A defective silencer fails to adequately reduce the noise produced by the exhaust, violating regulations regarding vehicle maintenance and permissible noise levels.
3. Driving fast in low gears increases engine RPM and results in greater noise output, which is not only unnecessary but also contrary to the principle of driving at a speed that is appropriate for the conditions.

In summary, each of these scenarios independently leads to excessive noise, and recognizing them highlights the necessity of responsible driving behavior as governed by German traffic laws to minimize environmental disturbances. Therefore, selecting all relevant options is important for a comprehensive understanding of how different actions contribute to noise pollution.