Final answer:
An organization that groups people with diverse occupational specialties by similar products, services, or regions is using a Divisional structure, which enhances specialized efficiency.
Step-by-step explanation:
When people with diverse occupational specialties are put together in formal groups by similar products or services, customers or clients, or geographic regions, the organization is using a Divisional structure. This approach is beneficial because it allows for specialization where workers can focus on the parts of the production process where they have an advantage, due to their skills, talents, and interests. These advantages may be influenced by various factors, including educational choices and geographic location, enabling them to be more effective and efficient in their specialized areas.