When leaving your vehicle unattended, what actions must you take?

The correct choice is comprehensive, encompassing essential safety and security measures that should be taken when leaving a vehicle unattended. Stopping the engine is crucial because it prevents any unintended movements, which can occur if the vehicle were to roll unexpectedly. Locking the ignition and removing the ignition key is necessary to deter theft and ensure that no one can accidentally start the vehicle while it is left alone. Setting the parking brake adds an additional layer of safety, ensuring that the vehicle remains stationary and does not roll away.

These actions form a complete checklist for responsible vehicle ownership and operation. Failing to perform any of these steps can lead to unnecessary risks, such as accidents or vehicle theft. Therefore, taking all of them together is the best practice.