Which source is most likely an authority on the subject?
A
Dr. Vale, a pediatrician, discusses electrical circuitry on her home-improvement website.B
Jonah, an amateur cook, teaches his son how to make the best grilled cheese sandwiches.C
Susan, an architect, presents her hand-made quilts at the Quilting Society.D
Dr. Patel, a cardiologist, presents her findings on heart disease.