Who Generally Initiated the Movement to Reform the Church

Who generally initiated the movement to reform the church?

A) Outside reformers outraged by clerical excesses such as the sale of church offices and debauched conduct by the clergy
B) Scholars at universities who looked askance at the corruption they saw in the church
C) High-ranking clergy who controlled churches and monasteries
D) The papacy, since it was trying to reconcile with eastern Orthodoxy and a church perceived as corrupt threatened those aspirations