In which situation should the operator of mobile equipment be cautious to avoid accidents?

The correct choice emphasizes the importance of situational awareness while operating mobile equipment, particularly when visibility is compromised. When there is an obstructed view to the rear, the operator faces significant risk since they may be unaware of pedestrians, other vehicles, or obstacles that could lead to collisions or accidents. This scenario requires extra caution, as the inability to see what is behind the equipment could easily result in harm to individuals or damage to property. Operators should utilize mirrors, cameras, or enlist ground personnel to aid in safe operation when visibility is limited.

In other circumstances mentioned, such as when control systems are activated, bad weather conditions, or when loading materials, while caution is still necessary, these situations do not inherently present the same immediate risk associated with obscured visibility. Furthermore, engaging in safe operating practices, such as ensuring clear sightlines and using appropriate procedures to mitigate risks, is particularly critical in scenarios where visibility is obstructed.