Final answer:
The correct source of internal data from the provided options is Sales records, essential for internal analysis and strategic decision-making within a business. Economic indicators, while crucial for broader economic understanding, represent external sources of data.
Step-by-step explanation:
The source of internal data among the options provided is b. Sales records. Internal data refers to the information that originates within the organization, typically generated through the company's own operations and transactions. Sales records capture critical data about transactions, customer purchases, revenue, and trends over time and are used for analysis and decision-making within the business. Other sources, such as tax records, could also be considered internal, but they are not listed in the question's options.
Economic indicators, such as gross domestic product, international trade statistics, and energy information, represent external data sources as they are measurements reflecting broader economic activities and are usually collected and analyzed by governmental agencies, economic analysts, or international organizations. These indicators help organizations make informed decisions regarding strategy and operations by understanding economic trends and their potential impact on the business environment.