Answer:
Correct answer is A. started discussions regarding abuses of the Church
Step-by-step explanation:
Option A is the correct one as they were opposing to the usual beliefs established in the church related to selling of indulgences, but also related to abuses that led to church being more political than religious institution.
B is not correct as a lot of them were even excommunicated from the Church.
C is not correct as this could totally different effect, they were not promoted, but often prosecuted by the church authorities.
D is also not correct as the question of taxation was related to the authority of the state.