Final answer:
A mechanistic structure with decentralization, wide span of control, and little formalization is characteristic of a hierarchical structure.
Step-by-step explanation:
A mechanistic structure is characteristic of a hierarchical structure. In a hierarchical structure, decision-making authority is concentrated at the top levels of the organization, resulting in a centralized and formalized approach. The wide span of control refers to the number of subordinates that a manager supervises directly, and little formalization suggests a more rigid and rule-driven environment. These characteristics align with a hierarchical structure.