What Belief Drove Monastic Movements for Religious Reform in the Tenth

What belief drove monastic movements for religious reform in the tenth and eleventh centuries?

A) The belief that there was no biblical justification for the existence of popes and bishops
B) The belief that the church had become too worldly and had been corrupted by its contacts with secular authorities
C) The belief that Islam threatened the heart of western Christianity and that only a spiritually pure church could combat this peril
D) The belief that secular rulers needed to exert more control over the church, which had become too corrupt