In what type of unit may a patient not be transported?

The correct answer indicates that a patient should not be transported in a marked unit. In the context of emergency medical services, a marked unit typically refers to an official vehicle, such as an ambulance or police car, that is clearly identifiable and equipped for specific official use. However, transporting a patient in a marked unit can raise concerns regarding public safety, legal compliance, and proper care protocols.

Marked units are often associated with official duties and may not be equipped for patient care, as they are designated for response to emergencies or law enforcement tasks. Hence, using them for patient transport could compromise the patient's well-being and the responsibilities of the unit.

In contrast, other options like unmarked units, personal vehicles, or private transports, might have varying levels of permissibility based on protocols, but they don't typically carry the same level of concern associated with marked units. For instance, personal vehicles might be used in non-emergency situations where there’s no immediate risk, and transportation can be handled by non-medical personnel if needed.