Which of the following is an example of an external source of information?

The choice indicating that interviewing potential customers is an external source of information is correct because it involves gathering data from individuals who are outside the organization. This method yields insights directly from the target market, allowing businesses to understand customer needs, preferences, and perceptions, which can be invaluable for strategic decision-making.

In contrast, sales reports, employee surveys, and payroll records are all internal sources of information. Sales reports provide data on past performance within the organization, while employee surveys collect feedback from current staff. Payroll records detail employee compensation and are part of internal operations. Thus, these sources do not reflect external perspectives but rather the internal workings and assessments of the company.