James Cross Giblin gives clear explanations of the important historical figures in ancient Egyptian history in The Riddle of the Rosetta Stone. Which detail from the The Riddle of the Rosetta Stone is the best evidence to support the thesis?

De Sacy, Akerblad, Young, Champollion, and others all made some progress in translating the demotic passage.
He decided the three hieroglyphs must represent the name of Thothmes, the "Child of Thoth," a pharaoh who ruled Egypt from 1501 to 1447 B. C.
Champollion had a chance to resolve this question when a fellow scholar sent him copies of some inscriptions from a temple that had been built long before the time of the Ptolemys.
Champollion succeeded in deciphering a large part of the passage, but the meaning of many hieroglyphs was still unknown when he did his major work in the 1820s.