Based on The Riddle of the Rosetta Stone, how do the findings of Jean-François Champollion differ from the findings of Thomas Young?

Unlike Young, Champollion used his knowledge of the Coptic language, which allowed him to decipher some of the hieroglyphs on the Rosetta Stone.
Unlike Young, Champollion changed the spelling of “Ptolemy” to “Ptolmis,” which allowed him to decipher some of the hieroglyphs on the Rosetta Stone.
Unlike Young, Champollion traveled to Egypt, which allowed him to study other hieroglyphic inscriptions and decipher the hieroglyphs on the Rosetta Stone.
Unlike Young, Champollion had extensive mathematics knowledge, which allowed him to decipher the hieroglyphs on the Rosetta Stone.