What question best investigates the authority of a source?

The question that best investigates the authority of a source is focused on the author's qualifications for writing on the subject. Understanding the qualifications involves assessing the author's education, expertise, professional background, and experience in the field related to the content. This is crucial for establishing whether the author possesses the knowledge and credibility necessary to provide accurate and trustworthy information.

Evaluating an author's qualifications can help readers determine if the source is trustworthy and valuable, especially in academic or professional contexts. Knowing that an author has relevant degrees, years of experience, or recognized contributions in their field significantly enhances the perception of their authority on the topic being discussed. This approach directly ties into the concept of authority, as it evaluates who is presenting the information and their capability to do so competently.

In contrast, the other options address different aspects of evaluating a source but do not directly assess the author's authority. For instance, reliability focuses on the accuracy of information, bias deals with objectivity, and depth of exploration relates to the comprehensiveness of the topic covered rather than the author's qualifications.