Final answer:
Louis IX supported the building of hospitals, schools, and monasteries in France.
Step-by-step explanation:
Louis IX, also known as Saint Louis, supported the building of hospitals, schools, and monasteries in France. Monasteries played a crucial role in the preservation of learning and knowledge in Western Europe, particularly after the collapse of the Roman Empire. Monks in monastic communities hand-copied books, many of which were works of Christian theology or classical Greek and Roman writings. Monasteries also served as centers of administration and nodes in communication networks. Therefore, the correct answer is C) Monasteries.