Which of the following is a warning signal that may indicate a problematic rental?

The choice that highlights a warning signal indicating a potentially problematic rental is that the customer appears unusually upset. When a renter demonstrates signs of distress or frustration, it may suggest issues such as dissatisfaction with previous rentals, fear of being taken advantage of, or concern about rental terms. This upset demeanor can be a critical indicator of underlying problems that could lead to complications during the rental process, such as disputes over pricing, rental conditions, or unexpected fees.

In contrast, being local may not be an inherently negative indicator, as many successful rentals occur with local customers who might have valid reasons for renting. Having excessive verifiable information can often indicate that the individual is being thorough and responsible, rather than signaling a problem. Arriving alone also does not generally suggest a red flag, as many individuals rent items or properties independently without issue.