Answer:
Correct answer is The Crusades in the Holy Land introduced Europeans to Eastern goods.
Step-by-step explanation:
Although it might sound strange the first option is correct because although Crusades were war campaign first of all, they opened a period of long trade between East and the West. This trade connection that first established lasted until the end of Middle Ages and was known as Silk Road.
Second option is not correct as it didn't had anything to do with the establishment of this connections.
Third option is not correct as guilds were trade organization established in Europe to protect traders.
Last option is not correct because this was the usual system in Middle Ages.