What is the right course of action?

You answered correctly! In this situation, both the tram and the motorcycle have the right of way, and you must let them go first.

Here's why: Trams almost always have priority at intersections, even when there's a yield sign for them, unless a police officer or signal gives clear instructions otherwise. Additionally, when making a left turn, you must give way to oncoming traffic—in this case, the motorcycle coming towards you.

So the correct action is to yield to both the tram and the motorcycle before you make your turn. This follows the German traffic rules for both trams and left-turning vehicles at intersections. If you remember these rules, you will be able to answer similar questions correctly in the future.