Which of the following about the Crusades is not true?
a. The rise of the Seljuk Empire was the immediate cause of the Crusades
b. The concern of European Christian leaders over the spread of the Islamic faith was a long term cause of the Crusades
c. The Crusades were unsuccessful from the beginning, met with strong opposition from the united Islamic world
d. In the aftermath of the Crusades the nations of Europe began to look inward