What is the title of the head of each NBI service?

The title of the head of each National Bureau of Investigation (NBI) service is recognized as Service Director. This designation distinctly identifies the individuals who lead specific services within the NBI structure, reflecting their authority and managerial responsibilities over specialized operational areas.

Understanding the hierarchical structure within law enforcement organizations like the NBI is vital, as each title conveys its role and function. The designation of Service Director ensures clarity in command and operational oversight, which is essential for effectively managing investigations and administrative duties within their designated service.

The choice of "Deputy Director" typically refers to an individual who assists the Director and does not head a specific service, while "Head Agent" does not align with the established terminology used within the NBI. The title "Director" could refer to the overall head of the NBI but not to the heads of individual services, which is why "Service Director" is the correct answer.