Final answer:
Managerial accounting is characterized by the creation of very detailed reports tailored to the internal needs of a firm, helping managers make informed decisions about the company's operations.
Step-by-step explanation:
The distinguishing feature of managerial accounting is C) very detailed reports. Unlike financial accounting, which focuses on providing information to external users such as shareholders and creditors through general-purpose reports, managerial accounting is concerned with providing detailed information to managers within the organization to aid in decision-making. These reports are often customized to the specific needs of the company and can include detailed analysis of products, revenues, costs, and profits which helps in the strategic planning and the management of the firm's operations.