An operator __________ is an interlock that prevents the operator from being in harm's way while the machine is in operation.

• A. Restraint
• B. Interlock
• C. Guard
• D. Shield

Answer: (A)

The key idea is protecting the operator by restricting movement to keep them out of the machine’s danger zone during operation. A restraint is a device or configuration that limits how far the operator can move or reach, effectively preventing exposure to hazards while the machine runs. When used as part of an interlock system, this restraint ensures the operator cannot stay in or move into the hazardous area, which is why it fits the description best.

Guard and shield are passive barriers that block access, but they don’t by themselves enforce safe positioning or stop the machine based on the operator’s location. An interlock is the control that links safety actions to the machine’s operation, whereas a restraint specifically serves to keep the operator out of harm’s way by limiting their movement. That combination is why restraint is the most appropriate choice.