Final answer:
At the C. strategic management level of an organization, decisions are most unstructured due to their complexity, long-term implications, and the high degree of uncertainty involved.
Step-by-step explanation:
Decisions at different levels of an organization have varying degrees of structure, with some being more unstructured than others. The level of organization where decisions are most unstructured is the C. strategic management level. Unlike operational decisions, which tend to be structured and routine, or tactical decisions, which are often semi-structured, strategic decisions deal with long-term planning and are highly complex and abstract. They typically involve uncertainty, complexity, and a lack of precedent, making them less routine and more unstructured. These decisions often require a deep analysis of external and internal factors, creative thinking, and deliberation among the top executives.