Geno is preparing a speech about how to appraise antique furniture. One of the sources he is relying on is a book by Harriet DuPont. DuPont holds a Ph.D. in chemistry and has spent over twenty years appraising items for auction at the esteemed auction house, Sotheby's. Her peers praise her as one of the best in the business. Out of this information, which detail would contribute the least toward establishing DuPont's trustworthiness as a source with Geno's listeners?

A. her experience appraising items
B. her reputation with her peers
C. her affiliation with Sotheby's
D. her advanced education

Answer: D