D. They improved conditions on slave ships to help more people survive.
One of the most important effect of the crusades was on commerce. They created a constant demand for the transportation of men and supplies. Hope this helped, have a great day! :D
Answer:
It would be important for the boys to know the geography of the area so that they don't get lost and if they did, they would be able to find their way back.
D. Concurrence is the answer
<span>They controlled colonies' government but gave colonies economic control.</span>