Although Frederick I Subdued the Northern Italian Communes, He Began

Although Frederick I subdued the northern Italian communes, he began the reversal of his own fortune when he

A) set German magistrates over the cities; their arrogance and despotism infuriated commoners and aristocrats alike.
B) granted the Italian cities self-governing powers, thus allowing a reassertion of northern Italian political independence.
C) permitted Italian bishops governance of the communes on the condition that they agree to serve under his name.
D) asserted that all German emperors were also emperors of Rome; this assertion hardened papal resistance to Frederick and alienated the aristocrats of northern Italy as well.