What Did Luther Admit During His Debate in July 1519

What did Luther admit during his debate in July 1519 with the Catholic theologian Johann Eck?

A) that he believed popes and even Church councils could err, as only scripture was infallible
B) that he considered the pope the most notorious sinner of all time
C) that the Catholic Church was under the control of the Antichrist
D) that baptism was of no importance
E) that the Holy Roman emperor was a tyrant and heretic