What Pushed the Irish to Leave Their Homeland in the 1840s

What pushed the Irish to leave their homeland in the 1840s and 1850s and come to the United States?

A) Stories and letters from relatives who had made it big in the U.S.
B) A potato famine which left many people starving and hopeless
C) Intolerance and persecution by the British for their Catholicism
D) Promises by agents from U.S. factories that good jobs awaited them in the U.S.
E) The quest for greater educational opportunities for their children