It is said that Europe escaped its isolation from the rest of the world during the High Middle Ages (1000 to 1300). What mostly contributed to this?

It is said that Europe escaped its isolation from the rest of the world during the High Middle Ages (1000 to 1300). What mostly contributed to this?
A) the creation of a new, rich merchant class
B) the Crusades
C) trade along the Silk Road from Europe to China
D) both B and CX