Which practice in the catholic church caused a rift between the papacy and the holy roman emperor?
a) changing the rules for appointments of church officers
b) forbidding catholic priests to marry
c) making latin the official language of the church

a) changing the rules for appointments of Church officers

Explanation: Because the Investiture Controversy was the most significant conflict between secular and religious powers in the medieval Europe. It began as a dispute in the 11th century between the Holy Roman Emperor Henry IV, and the Gregorian concerning who would control appointments of church officials .

the answer wold be b) travel among nations should be regulated by an international organization