Which of the following best summarizes the accommodations airlines must provide?

The correct choice highlights the comprehensive support that airlines are mandated to provide for passengers with disabilities, specifically in the context of boarding and deplaning. The Air Carrier Access Act mandates that airlines must offer reasonable accommodations to ensure that individuals with disabilities can access the same level of service as other passengers.

This includes assistance with boarding the aircraft, securing a seat, and deplaning upon arrival. Comprehensive support encompasses not only physical assistance but also effective communication, as well as any necessary services that allow individuals with disabilities to travel comfortably and safely.

In contrast, the other options are too narrow in focus. Assistance limited to only physical aid at the airport or baggage claims does not cover the full spectrum of needs that passengers with disabilities might encounter during their travel experience. Priority boarding, while a helpful measure, does not encapsulate the broader responsibilities airlines hold in ensuring accessibility throughout the entire travel process. Thus, the comprehensive support detailed in the correct answer aligns with the intent of the Air Carrier Access Act to provide equal travel opportunities for all passengers.