Which nursing professional has the maximum span of control?

The nurse manager typically possesses the maximum span of control among the given options. This is because a nurse manager is responsible for overseeing multiple nursing staff and operations within a specific unit or department. Their role involves not only managing day-to-day activities but also making critical decisions related to staffing, budgeting, and departmental policies. Due to these responsibilities, they often supervise a sizable team of registered nurses, charge nurses, and possibly other roles, which enables them to have a broader control over various functions and staff dynamics.

In contrast, registered nurses primarily focus on patient care and may be part of a smaller team under the leadership of a nurse manager or charge nurse. Charge nurses have a specific role that includes overseeing a designated group of nurses during particular shifts, but their supervisory scope is typically limited compared to that of a nurse manager. Clinical nurse specialists often focus more on providing expert clinical guidance rather than on supervisory responsibilities, which also limits their span of control. Thus, the role of nurse manager inherently involves a wider supervisory and operational breadth, making it the correct answer.