What is one piece of information a Class A employee must determine when requesting a clearance?

When requesting a clearance, a Class A employee must determine the time required to complete the work because it is critical for coordinating the safety and scheduling of operations in the area. Knowing the duration of the task helps ensure that other train operations can be effectively managed and that personnel can safely work without interruptions. Establishing a clear timeframe allows for better scheduling of trains and helps minimize disruptions in service, ensuring that safety protocols are adhered to throughout the clearance duration.

The other options might pertain to different aspects of the work process but do not directly relate to the clearance request itself as fundamentally as the required time. For instance, while knowing the number of personnel, specific tools, and voltage levels might be useful aspects of overall job preparation, they do not play a decisive role in the safety and operational planning that accompanies requesting a clearance.