Trade was the motivating factor. The silk road accross Asia was besieged by bandits & required bribes to a number of nations to transport goods to & from Asia. Therefore a sea route would be a much safer & less expensive means of getting trade goods to & from Asia.
It could be argued that one good thing that resulted from the crusades was that there was cultural diffusion, but the bad thing was that thousands of lives were lost.
The State of the Union, though valuable, is not completely necessary. Choose D.