Final answer:
Saint Teresa of Avila made a significant contribution to the Catholic faith by founding the Discalced Carmelites and emphasizing the importance of prayer and personal relationship with God. The correct option is C.
Step-by-step explanation:
Saint Teresa of Avila, a Spanish nun, made significant contributions to the Catholic faith during the Catholic Reformation.
She founded a new Catholic religious order called the Discalced Carmelites, also known as the Order of the Barefoot Carmelites. This order was dedicated to a more contemplative and austere form of religious life.
Through her writings and teachings, Saint Teresa emphasized the importance of prayer, meditation, and personal relationship with God, which had a profound impact on the spiritual life of Catholic believers.