Final answer:
A simple business structure is characterized by a flat hierarchy, basic differences in work specialization, and low formalization, which foster open communication and flexibility within the business.
Step-by-step explanation:
The characteristics of a simple business structure include a flat organizational hierarchy, very basic differences in work specialization, and low formalization. In such a structure, there are typically few layers of management, which allows for more open communication and less stringent control over processes. Employees may have a broad range of responsibilities rather than highly specialized roles. This often leads to greater flexibility within the business but may also result in less clear procedures and protocols. The correct answer to the question is A. flat, very basic differences in work specialization, low formalization.