The correct answer is C. Monks in monasteries
Explanation:
A monopoly occurs as only a few people control a specific product or service. In the case of the Middle Ages (5th century to 15th century) monks held a virtual monopoly on learning because they were the ones that educated the population in most cases, this included the high class but also part of the lower classes. Moreover, monks were almost the only ones that had free access to all kinds of texts as these were kept in libraries within the monasteries and monks made copies of these. This explains why during this time monastic schools and cathedral schools were the most common schools.
