Who might have said the quote below? i want to purify the church. (this question is on my study guide for the reformation quiz so it would be about the catholic church in the 1400's

Any of the early reformers would have expressed the sentiment, "I want to purify the church."

That is not so much a quotation from a specific reformer as it describes the aim of the reformers in general.  John Wycliffe was a 14th century English reformer.  Jan Hus, a Bohemian reformer, began his career as a priest right at the beginning of the 15th century (in 1400).  Either of them would have seen their work as an effort to purify the church, as would later reformers in the 16th century such as Martin Luther and John Calvin.