In this situation, why do you have to wait before turning left?

Your answer is correct because, according to German traffic rules, when turning left, you must yield to any oncoming vehicles going straight or turning right. In this case, the motorbike is approaching from the opposite direction, so you must wait for it to pass before turning left. The red car and the cyclist do not have priority over your turn in this scenario. This rule helps prevent collisions by ensuring the turning vehicle does not interfere with oncoming traffic that has the right of way. Remember, always look out for oncoming vehicles and yield to them when making left turns at intersections without specific traffic signals granting you priority.