Question

this method of travel benefits hotels, car rental agencies, and cruise lines in addition to making international travel much easier.
air travel
high - speed rail
cross - country bus
cruise

Explanation:

Air travel is a common way of international travel. It can lead to increased business for hotels (due to overnight stays), car - rental agencies (for ground transportation at the destination), and cruise lines (as some travelers may combine air travel with a cruise). High - speed rail, cross - country bus, and cruise are more limited in their ability to make international travel as easy as air travel does in general.

Answer:

A. Air travel