What is the minimum distance between your vehicle and any school bus when its stop arm is extended?

Answer: C — 15 feet

When a school bus stop arm is extended, it signals the presence of children entering or exiting the bus. Therefore, it is important to maintain a safe distance to avoid any potential accidents. Option A (10 feet) is incorrect because this distance is insufficient to ensure the safety of both the children and the driver. Option B (12 feet) is also incorrect as it is still not enough distance to prevent a collision with the school bus. Option D (20 feet) is incorrect because it is too far and may cause confusion for other drivers and pedestrians. The minimum recommended distance is option C (15 feet), which allows for a safe stopping distance for drivers and adequate space for students to safely enter and exit the bus.