Choose from the statements below the one that represents a significant difference between the first crusade and the second crusade.
a. the first crusade was an attempt to conquer damascus, while the second was not.
b. the first crusade was initiated by a pope, while the second one was not.
c. the first crusade was highly successful, while the second one was not.
d. the first crusade was an attempt to conquer islamic lands, while the second was not.