The correct answer is C. They were spiritual leaders who also exercised secular power.
Explanation:
The Middle Ages was the period that followed the end of the Classical period, during it, European societies focused on the church, religion, and faith and were organized in a fixed social hierarchy in which the pope and the King were the head of the state. This implies the popes acted as spiritual leaders because they hold the higher position in the clergy and therefore were in charge of spreading faith and guaranteeing all the structure of the church was preserved, but besides this popes were in charge of taking decisions related to society and government that were not related to faith or religion and therefore were secular. This means, during the Middle ages popes were spiritual leaders who also exercised secular power.