When must you switch on the hazard lights on your vehicle?

You were correct to choose options 1 and 2. According to German traffic rules, hazard lights must be used when your vehicle experiences a breakdown in a place where it is difficult for other drivers to see, as this warns others to be cautious. They must also be switched on when your vehicle is being towed to signal an unusual situation to other road users. However, using hazard lights when briefly double-parked is not allowed, as it does not justify signaling a hazard to other drivers. This distinction helps ensure hazard lights are used appropriately to increase safety on the road.