What type of passenger has been tagged for travel among multiple airlines?

The correct choice identifies a passenger whose baggage is tagged in a way that allows it to transfer seamlessly between multiple airlines during their journey. Interline baggage refers to the luggage that can be checked in through one airline and then automatically transferred to connecting flights operated by partner airlines. This system is essential for managing flights where passengers do not have to reclaim and recheck their bags during layovers, making the travel experience smoother and more efficient.

Other types of passengers listed in the options do not pertain specifically to the tagging of baggage among multiple airlines. An inadmissible passenger refers to someone who cannot enter a country due to immigration rules. A landing passenger is typically someone who disembarks at a stopover but does not continue on the same aircraft. A left behind passenger is a term that indicates a traveler who has missed their flight or is not accounted for at the destination. Hence, interline baggage is the only option that accurately reflects the situation of a passenger associated with travel across multiple airlines.