Final answer:
The most effective organizational structure for maintaining centralized authority and accountability of specialized departments is a functional structure.
Step-by-step explanation:
The organizational structure that would be most effective for maintaining centralized authority and accountability of specialized departments is B. Functional. In a functional organizational structure, departments are grouped based on their common functions or activities. This allows for centralized authority and clear lines of accountability within each department. For example, in a functional structure, all marketing staff would be grouped together under the marketing department, which is headed by a marketing manager.