Final answer:
When backing up with a guide, it's critical to maintain visibility of the guide and ensure they have a clear view of the backing path, avoiding the blind side for safety.
Step-by-step explanation:
When backing up using a guide, the correct actions to ensure safety and efficiency are to be able to see the guide throughout the maneuver and position your guide where there is a clear, continuous view of your backing path. This means that options (a) and (c) are correct, making (d) the correct answer. It is important not to back into your blind side, as that increases the risk of an accident. Instead, having a clear view of the guide and making sure the guide has a good vantage point over your path can greatly reduce the risk and make the backing process smoother. When backing up with a guide, it's critical to maintain visibility of the guide and ensure they have a clear view of the backing path, avoiding the blind side for safety.