What is correct in this situation?

In this situation, the correct choices are about reducing your speed and recognizing that the truck has the right of way.

According to German traffic rules, when approaching a junction with a truck or larger vehicle, you must be aware that such vehicles often have right of way due to their size and operational constraints. Thus, you should reduce your speed to assess the situation safely and potentially yield to the truck if it is already in the intersection.

The choice indicating that the truck has to wait is incorrect because, in many cases, larger vehicles may have the right of way depending on the road signs and layout. Understanding this rule helps promote safety and fluid traffic flow, especially in complex intersections.