Which of the following is a symptom of a potential mechanical issue in a crane?

The selection of unexpected or erratic movements as a symptom of a potential mechanical issue in a crane is justified because such behavior can indicate underlying problems with the crane's mechanical systems. These movements might result from various factors, including worn-out components, misalignment, or issues within the hydraulic or electrical systems that govern the crane's operations. Unpredictable or jerky motions are warning signs that something may be malfunctioning or not functioning as intended, which can compromise safety during operations.

In contrast, smooth operation without any noise indicates that the crane is functioning properly, as does the stable lifting of loads, which suggests the lifting mechanism is in good working order. Easy control of the load also points to the effective functioning of the crane’s control systems. Therefore, unexpected or erratic movements stand out as a clear sign of potential mechanical issues that could lead to safety hazards if not addressed promptly.