I believe the answer is: d. reformation
The reformation is led by a figure named Martin Luther, who voiced up his believe that the action made by Catholic church to sell indulgences for people who wanted to confess is a sin. This reformation ended up divided Christian religion into two (Catholic and Protestant)
D. Reformation
The Reformation began in 1517 after Martin Luther wrote his 95 Theses criticizing the Catholic Church.
Those supporting and agreeing with Martin Luther separated from the Church and began a new religion--Lutheranism. Others followed separating from the Catholic Church over differing viewpoints from baptism, confession, social behavior, and structure of the religion. Separating religions were called Protestant religions because they were protesting the Catholic Church