Which of the following scenarios is NOT an example of an arriving alien?

The scenario involving a U.S. citizen returning from abroad is not characterized as an arriving alien. An arriving alien specifically refers to a non-citizen who is seeking entry into the United States. U.S. citizens, by their inherent status, have the right to return to the U.S. and are not subject to the same entry processes as immigrants or non-immigrants. Thus, they do not fall under the definition of "arriving alien," which pertains exclusively to foreign nationals who may or may not meet the requirements for admission.

In contrast, the other options depict situations involving non-citizens attempting to enter the U.S.: individuals seeking transit without seeking entry, non-citizens brought to the U.S. after being interdicted at sea, and those attempting to enter at a designated port-of-entry—all of which fit the definition of arriving aliens because they involve individuals who are not U.S. citizens and who are seeking permission to enter the country.