When should a driver check their mirrors more frequently while towing?

Answer: C — At all times to monitor the trailer

The correct answer emphasizes the importance of consistently checking mirrors while towing. This practice is crucial because towing a trailer significantly changes the vehicle's dynamics and visibility on the road. By monitoring the mirrors regularly, a driver can stay aware of the trailer's position and any obstacles or vehicles that may be near it. This vigilance helps in avoiding accidents and ensuring safe maneuvering, especially since trailers often have blind spots that cannot be easily seen through the vehicle’s rearview mirror. While it might seem sufficient to check mirrors only during specific situations like turns or stops, doing so at all times provides a comprehensive awareness of the driving environment. This ongoing monitoring is essential for safe towing, especially on highways where speed and traffic can increase the potential for danger.