Why should you be ready to brake in this situation?

You selected the correct answer: you should be ready to brake because of the tractor. In German traffic situations, when approaching slower agricultural vehicles like a tractor—especially on rural roads—you must always be prepared to reduce speed or stop. Tractors can move slowly, may turn suddenly onto a field, or might not be as easily visible around curves. The presence of a tractor ahead is a specific reason to anticipate a need to brake, while the speed limit or the presence of a motorbike were not primary risks in this scenario. This rule helps ensure safe distances and allows enough reaction time to unexpected changes on the road. Always pay attention to slow-moving vehicles as they often require drivers behind them to adjust speed or prepare to stop.