Answer:
A. silk
Step-by-step explanation:
The Crusaders encountered lot of things with which the Europeans were not familiar, some of which were goods, while others were technological advancements. One of the things that turned out to be very attractive for the European market was the silk. The silk was not something new, as the Chinese have been producing and using it for a very long time, just that the Europeans were not aware of it. It was a beautiful material for making clothes of good quality and excellent aesthetics. It was a good that was immediately very demanded and expensive, so lot of effort was put into engaging in trade to get silk. The silk turned out not just to very good for making clothes, but it was also used by the soldiers, as it was partially helping in stopping the spears and bows, and it was reducing the damage.