"The number of subordinates that can be effectively managed by a superior" is referred to as:

Option 1 -> Functional structure refers to organizing employees based on their specialized functions or departments (like marketing, finance, HR), not about the number of subordinates.

Option 2 -> Divisional structure refers to organizing the company into semi-autonomous divisions based on products, geography, or markets, not the number of subordinates a manager handles.

Option 3 -> Span of management (also called span of control) specifically defines the number of subordinates that can be effectively supervised and managed by a superior.

Option 4 -> Formal organisation refers to the officially defined organizational structure with established hierarchy, rules, and responsibilities, not specifically about subordinate count.

Hence, Option 3: Span of management -> This is the correct management principle that specifically defines the optimal number of subordinates a manager can effectively supervise, direct, and control. It helps determine organizational hierarchy levels and managerial workload -> correct