How did indulgences lead to conflict amongst the churches

It showed people the corruptness of the churches in the era. People realized that the church was used mostly for profit, and that selling indulgences would never "forgive them of their sins" as sellers claimed. It caused Martin Luther to publicly put down the church, leading to a new branch of Protestantism called Lutheranism. The selling  of indulgences would ultimately split up the church in clashing ideals and thoughts on access to the Bible, as well as how it should be interpreted.

peasants’ war, (1524–25) peasant uprising in germany inspired by changes brought by the reformation, peasants in western and southern germany invoked   divine law to demand agrarian rights and freedom from oppression by nobles and landlords. as the uprising spread, some peasant groups organized armies. although the revolt was supported huldrych zwingli and thomas müntzerits condemnation by martain luther contributed to its defeat, principally by the army of the swabian league. some 100,000 peasants were killed. reprisals and increased restrictions discouraged further attempts to improve the peasants’ plight.

i think it would be " a" i might be wrong tho