What should you do?

Your answer is correct because before making a left turn at an intersection with a central divide, German traffic rules require you to stop before the turn and keep the central divide clear. This ensures that the intersection remains safe and prevents blocking traffic or obstructing other vehicles waiting in the center. Turning smoothly without stopping in the divide or stopping inside it is not allowed, as it can create dangerous situations and disrupt the flow of traffic. Stopping before the turn and leaving the central divide free helps maintain order and safety at intersections.