In a valid DEA number, what must the first letter be?

In a valid DEA number, the first letter must be either A or B. This is because DEA numbers are assigned to practitioners who are authorized to prescribe controlled substances. The letter A is generally assigned to physicians, while the letter B is assigned to mid-level practitioners such as nurse practitioners and physician assistants who are also licensed to prescribe in the United States.

This structure assists in quickly identifying the type of practitioner associated with the DEA number, which is crucial in ensuring that prescriptions are legitimate and comply with federal regulations regarding controlled substances. Understanding the different designations helps pharmacists verify the credentials of the prescriber and maintain compliance with the Drug Enforcement Administration's guidelines.

The other options presented do not conform to the established regulations regarding DEA number prefixes, as they include letters that are not historically associated with valid DEA numbers for practitioners. This is why the correct response regarding the first letter must be A or B.