What is the right course of action?

Your answer is correct because the situation involves traffic priority rules in an intersection with a priority road, indicated by the yellow diamond sign. According to German traffic rules, vehicles on the priority road have the right of way.

Here’s why the selected actions are correct:

1. Turning only after the motorcycle: The motorcycle is coming from your right direction on the priority road. You must wait for it to pass first because it has the right of way.

2. Turning before the yellow car: The yellow car is coming from your left, and it is on a yield or secondary road (no priority sign). Since you are on the priority road, you can safely proceed before the yellow car.

You should not be first to make your turn, as the motorcycle on the priority road must go first. This ensures safe and orderly traffic flow by respecting right of way on priority roads.