Which devices should be checked before operating a TLB?

Prior to operating a Tractor Loader Backhoe (TLB), it is crucial to ensure that safety features and operational devices are functional, which is why the correct choice focuses on reverse warning alarms, seat belts, and guards. Reverse warning alarms are essential for alerting nearby individuals that the equipment is moving in reverse, significantly reducing the risk of accidents.

Seat belts are a critical safety component that protects the operator during operation; they must always be used whenever heavy machinery is in use to minimize the risk of injury in case of an accident or rollover. Guards, which are designed to prevent access to moving parts or hazardous areas, help protect both the operator and anyone in proximity to the machine by mitigating risks associated with equipment operation.

In contrast, while speedometers, temperature gauges, and mirrors are important for general vehicle operation, they do not specifically enhance safety in the context of the TLB's functionality. GPS navigation is typically not relevant for equipment operation checks, and headlights, while necessary for visibility, do not directly relate to the immediate safety concerns associated with pre-operation checks before using a TLB. Thus, focusing on the reverse warning alarms, seat belts, and guards ensures that the operator and those around them are protected during operation.