What was the effect of european christians wanting to recover the holy land from the muslims?
the crusades
the middle ages
the manor system

It was the Crusades.  The Crusades was a campaign to regain the Holy Land from the Muslim invaders after they took it over.  Some came to fight for that goal while others joined to see new lands while some were after the riches that be taken from that area.  Many were promised forgiveness of their sins if they joined the Crusades.  Still, some of the effects of the Crusade were that the Mediterranean was open to trade as soldiers and markets were established.  Other effects were that it led to the growth of towns and cities as the nobility sold their lands to join the Crusades and the people gained their freedom. Finally with the growth of towns, feudalism was weakened.

The answer to the question is a.