You need to check your mirrors ___________ and ___________ any turning movements to monitor the tail swing.

Answer: C — before, during

The correct choice emphasizes the importance of safety and awareness during the entire turning process of a school bus. Checking your mirrors before a turn ensures that you are aware of any surrounding vehicles, pedestrians, or obstacles that could be affected by your movement. This initial check allows you to assess the area and maneuver safely. During the turn, continuously monitoring your mirrors is crucial for capturing the bus's tail swing, which extends outwards and may impact nearby vehicles or structures. Keeping an eye on the mirrors while turning helps prevent potential accidents by ensuring that the back of the bus does not collide with anything behind it. Therefore, the process is ongoing: you assess the environment before initiating the turn and maintain awareness throughout the maneuver. This comprehensive approach to mirror checks significantly enhances safety for both the bus driver and those around them.