Which of the following rules of the road requires you to stop before turning right?

Your answer is correct because both the stop sign (first image) and the right-turn green arrow with a red light (second image) require you to stop before turning right.

The stop sign means you must come to a complete stop and only proceed when it is safe. This applies to all directions, including right turns.

The traffic light with a red signal and a green arrow pointing right means you may only turn right if you stop first and yield to any other traffic or pedestrians. Even though the green arrow indicates permission to turn right, the red light requires stopping first.

The third image, a priority warning sign for an intersection, does not require a stop before turning right. It only informs you about the road layout and who has the right of way.

In summary, stop signs and right-turn green arrows combined with red lights both require stopping before turning right under German traffic rules. This is to ensure safety and proper yielding.