What is the right course of action?

In this scenario, the correct actions involve allowing both the blue truck to pass and the tractor to make a turn.

According to German traffic rules, vehicles at a yield sign must give way to those already in the intersection or approaching it. In this case, the truck and tractor have priority based on their positions.

By allowing the blue truck to pass through and the tractor to turn, you ensure safety and compliance with traffic regulations. Not recognizing these situations could lead to accidents or traffic violations. Always assess the road and surrounding vehicles before proceeding.