Final answer:
The question about a company's internal organizational structure is not relevant when thinking strategically about a company's external environment. Instead, questions about market power, product similarity, and new firm entry are considered when assessing the external market structure.
Step-by-step explanation:
In thinking strategically about a company's external environment, the question that is NOT relevant is: C. What is the company's internal organizational structure? This question pertains to the company's internal environment rather than its external one. When evaluating the external environment, key strategic questions include determining the industry's dominant economic features, understanding the driving forces of industry change, and assessing the competitive market positions occupied by rivals. These elements give insight into questions such as how much market power each firm in the industry possesses, how similar products are across firms, and the ease of entry for new firms into the industry.