Which conduct is right?

Your answer is fully correct. Here's why:

In this situation, even though the traffic light appears red, the green car (which is directly ahead and turning right) is facing a yield sign, not a red traffic light that applies to it at this moment. Yield signs mean you must give priority to other traffic but do not necessarily require you to stop if the way is clear.

The key German traffic rule here is that when traffic signs (like yield signs) and traffic lights contradict each other, the traffic signs usually take precedence if they apply to your direction of travel. The green car must wait to give way as indicated by the yield sign.

For your own vehicle, you may proceed to turn right while observing the traffic signs, since you have the green arrow sign indicating permission to turn right, even if the main traffic light is red.

The third option is incorrect because the green arrow allows you to turn right without waiting for the main traffic light to turn green. This is a common German traffic rule: a green arrow light means you may turn right after stopping and yielding where necessary, regardless of the main light.

So, the correct conduct is that the green car must wait (due to yield sign) and you may turn right according to the green arrow, not only when the main lights show green.