What is the right course of action?

Your answer to slow down is correct because in situations where potential hazards exist—such as approaching a bus stop, parked vehicles, or pedestrians nearby—reducing speed increases safety. German traffic rules emphasize cautious driving especially in built-up areas and near bus stops where passengers might step onto the road unexpectedly. Accelerating or swerving unnecessarily can increase the risk of accidents. Therefore, slowing down allows you more time to react, maintain control, and ensure the safety of all road users. This approach aligns with the general principle of driving defensively and prioritizing safety in complex traffic environments.