The Barbary pirates were seizing US ships for ransom. One time with two British frigates near bye. That forced a change in Jefferson and he realized he had to have a Navy. He order the Constitution class frigates and some smaller vessels. The start of the blue-water Navy.
Its D - Most africans being transported to the US would likely die on the ships because of the extremely poor conditions before they even reached their deplorable fate.
hope this helps :)
U.A.E got it's independence on 2nd December 1971.
Hope this Helps!
