The flat earth society says that the earth is a flat circle, with the north pole at the center and giant mountains of ice around the circumference to keep boats and planes from going off the edge. so i guess the earth is flat after all. a. inappropriate appeal to authority; the source has been cited incorrectlyb. inappropriate appeal to authority; source's claim conflicts with expert opinion and reliability of the source is questionablec. inappropriate appeal to authority; the issue cannot be settled by expert opiniond. no fallacy