Answer:
The answer is: letter C. The Jesuits practiced the spiritual beliefs necessary to reform the Church and restore the piety of the clergy.
Step-by-step explanation:
The "Counter-Reformation" was a Jesuit movement led by Ignatius Loyola, a soldier-turned priest. The movement served as a response to the Protestant Reformation (a movement which challenged the Roman Catholic Church).
Besides this, it was also directed towards the "internal renewal" meant to restore the piety of the clergy. It also aided in the conversion of many people into Christians, such as the Muslims. In order to do this, the priests were trained in their spiritual beliefs in order to support the spiritual foundation of religious beliefs. The Jesuits then practiced the spiritual beliefs in order to reform the Church.
Thus, this explains the answer.