Which statement about the purpose of a safety interlock switch?

• A. It senses whether the guard is in place.
• B. It controls lubrication.
• C. It measures temperature.
• D. It starts the motor.

Answer: (A)

A safety interlock switch is designed to verify that a safety guard or door is closed before the machine can operate. When the guard is in place, the switch completes the control circuit, allowing the machine to start or continue a cycle. If the guard is opened, the interlock opens the circuit and stops the machine, preventing exposure to moving parts. This direct connection to the guard’s status is why it’s the best choice: the interlock’s primary role is to enforce that safety barrier is present.

Other options don’t fit because lubrication control, temperature sensing, and starting the motor are handled by different systems or components (lubrication systems, temperature sensors, and motor starters, respectively).