A Major Source of Mechanical Power in Medieval Europe After

A major source of mechanical power in medieval Europe after 1050 was the:

A) four-wheeled cart,which was pulled by horse or oxen.
B) water mill,which was used to grind grain,crush paper pulp,and press oil.
C) windmill,which was used primarily to process cloth.
D) steam engine,which was used to produce cloth goods.
E) open-hearth furnace,which was used to forge iron.