Concept:Span of control depends on the superior officer’s personal ability and preference.Explanation:Unity of command and unity of direction are fixed management principles, not personal choices.Delegation of authority is a formal process of assigning duties and powers.Span of control is the number of subordinates directly supervised by an officer.The number a superior officer can effectively handle varies with personal style and preference.So, span of control is a matter of personal preference.Answer:B. Span of control