In His on the Falsely Believed and Forged Donation of Constantine

In his On the Falsely Believed and Forged Donation of Constantine, Valla proved that

A) Emperor Constantine had, in fact, given the pope the western half of the Roman Empire to rule.
B) while the document was authentic, spiritual and legal reasons made it invalid.
C) the language in which the document was written indicated it was an eighth-century forgery.
D) the matter of the document's authenticity is irrelevant.
E) the document's use of diadem was not described correctly, and not in use at the time of the document.