Final answer:
The Crusades had a positive economic impact on medieval Europe by increasing commercial activities and stimulating trade with the East.
Step-by-step explanation:
The economic impact of the Crusades on medieval Europe led to an increase in commercial activities (C). While the Crusades were primarily focused on religious goals, they also brought about significant changes in trade and commerce. As Christian Crusaders traveled to the Holy Land, they interacted with different cultures and acquired new goods, such as silk and spices, which sparked a demand for these products in Europe. This resulted in the establishment of new trade routes, the growth of Italian city-states (such as Venice and Genoa) as trade centers, and an overall expansion of European trade with the East.