The Catholic Church was challenged on its teachings regarding penance (repentance of sin), indulgences (removal of guilt), and the authority of the pope. This led to the beginning of the Protestant Reformation when Martin Luther posted which of these documents on the doors of Castle Church in defiance of Rome?

A.
the 95 Theses
B.
on the Papacy in Rome
C.
sermon on Good Works
D.
work on the Psalms