What additional safety measure should be in place for the car?

The choice of tied off as an additional safety measure for the car is crucial in the context of installing and servicing jacks. Tying off a vehicle ensures that it remains securely positioned while mechanical work is being performed. This action helps prevent the vehicle from rolling or shifting unexpectedly, which could pose significant risks to the workers involved and potentially cause injury or equipment damage.

In many settings, especially in automotive service environments, vehicles can roll or tip if not properly secured, particularly on uneven surfaces or if jacks are improperly used. By utilizing a tied-off method, such as using wheel chocks or other restraints, the vehicle is stabilized, adding a layer of safety to the work area.

The other options, while they have their benefits in ensuring safety or functionality, do not provide the same level of immediate prevention against movement during maintenance. For instance, visual inspection is important for understanding the vehicle's condition but does not actively prevent movement. Similarly, securing with ropes may not be a reliable or standard practice in automotive contexts. Fitting the car with alarms could alert technicians to unauthorized movements but wouldn’t prevent them in the first place. Therefore, tying off the car represents the most effective and practical safeguard in this scenario.