Which statement about electronic tickets is true?

The statement that electronic tickets can track passenger usage without paper documents is accurate. Electronic tickets, or e-tickets, are digital versions of traditional paper tickets and have become standard in the airline industry. They enable airlines to manage and track travel itineraries and passenger information electronically. This system eliminates the need for physical tickets, making it easier for both airlines and passengers to handle bookings, changes, and cancellations.

The digital format of e-tickets allows for efficient tracking of passenger usage, such as boarding and itinerary modifications, which can be accessed via databases. Additionally, e-tickets streamline the check-in process, as passengers can typically show identification and their electronic ticket information directly on their mobile devices or through confirmation emails, further reducing reliance on paper documents.

Other options present limitations or inaccuracies regarding electronic tickets. For instance, e-tickets are valid for both domestic and international flights, so the claims pertaining to their restrictions are incorrect. Furthermore, e-tickets do not require physical tickets to verify travel as they function independently of paper tickets.