The correct answer is D) the author’s area of expertise.
The information about the source’s creator that would be most helpful would be the author’s area of expertise.
The information that would be most helpful to me would be the area of expertise of the author to decide if the secondary source found is valid. Let’s remind that a primary source is only those pieces of information directly from the time of history being researched. It could be direct testimonials, original photographs or film, or original interviews. To know if the secondary source would be valid, it is very important to know the background of the author on the topic, its experience, past researches or documents.