Final answer:
Promoting literacy was not a method used by the Catholic Church for direct financial gain, whereas selling indulgences, collecting tithes, and establishing monasteries were. Literacy efforts by monasteries aimed to preserve knowledge and religious texts.
Step-by-step explanation:
The notable means by which the medieval and early modern Catholic Church enriched itself included: selling indulgences, collecting tithes, and establishing monasteries. However, promoting literacy was not a direct means of enriching the Church. While the Church did play a role in literacy through the monasteries, which became centers of learning and where manuscripts were hand-copied, this activity was motivated more by a desire to preserve knowledge and religious texts rather than as a direct means of financial enrichment.
The sale of indulgences was a significant source of income for the Church, as it was believed that indulgences could reduce the time a soul spent in purgatory. This practice was one of the key issues that prompted Martin Luther to initiate the Protestant Reformation. Tithes, which were a portion of a person's income given to the church, also served as an important revenue stream.
While monasteries did engage in economic activities, their primary role was preservation and dissemination of knowledge, especially before the printing press was invented. They transcribed books, including the Bible and classical texts, vital for the preservation of written works from antiquity.