One long-term effect of the crusades was the
(1) development of pax mongolia
(2) fall of the ming dynasty
(3) control of jerusalem by europeans
(4) growth of trade and towns in western europe

The correct answer is (3) control of Jerusalem by Europeans

Jerusalem was in control by the Muslims from that area. When the first crusade was initiated it was done so to retake Jerusalem from the Muslims. The Europeans managed to do this and a long period of time passed before Muslims managed to reclaim it again for themselves. In the meantime, the Europeans had Jerusalem and tried to control the area.