During a lost communication scenario, what is the first route option you should follow?

In a lost communication scenario, the appropriate course of action is to follow the assigned route. This is because, during your last communication with air traffic control (ATC), they would have provided you with specific routing instructions to safely navigate through controlled airspace. The assigned route is recognized as the safest option to maintain air traffic flow and ensure you're following the proper airways as directed by ATC.

If you were to default to the expected, filed, or vectored routes at this stage, you might not be adhering to the last set of instructions given by ATC, which is critical in maintaining safe separation from other air traffic. The assigned route is the most directly relevant instruction before losing communication, which should guide your actions until you can re-establish contact or land safely. Following this protocol helps to minimize the risk of conflicts with other aircraft and ensures compliance with ATC guidance.