Final answer:
The administrative information for an EMT's prehospital care report includes the emergency service and incident identification details, such as 'BLS Unit 51-20; Incident # 67-8971-90'.
Step-by-step explanation:
The item that an EMT (Emergency Medical Technician) would place in the administrative information section of the prehospital care report is B. "BLS Unit 51-20; Incident # 67-8971-90". This information pertains to the emergency service and incident identification, which are administrative details necessary for reports and potential follow-up. It is separate from the patient's condition or the situation in which they were found, which would be recorded in different sections of the report.