What action should you take to turn on the parking lights?

To turn on the parking lights of the Joint Light Tactical Vehicle (JLTV), utilizing the headlights and clearance lights switch is the appropriate action. This switch is specifically designed to control the vehicle's exterior lighting system, including parking lights. Engaging this switch allows the operator to activate the parking lights, which are essential for visibility and safety when the vehicle is stationary in low light conditions.

The other options do not accomplish this task; for instance, pressing the ignition button is intended to start the vehicle, while toggling the parking brake typically serves a different operational function related to securing the vehicle when parked. Activating the key fob is primarily for remote features like locking or unlocking doors and may not influence the vehicle's lighting system at all. Understanding the purpose and function of the headlights and clearance lights switch is crucial for effectively managing the vehicle’s lighting systems in various situations.