What is the right thing to do?

In this situation, you must give way to the green car. This is because you are turning left, and the green car is coming from the opposite direction and going straight or turning right. According to German traffic rules, when turning left at an intersection, you must give way to oncoming traffic going straight or turning right. The red car, coming from your right, must also yield because it is entering the main road from a side road. So, the correct action is to yield to the green car before making your turn. This is why answer 1, "I give way to the green car," is correct. This rule helps prevent accidents at intersections by clearly defining who has priority.