Although Viking Raids Often Devastated Towns,the Vikings Also Revitalized Cities

Although Viking raids often devastated towns,the Vikings also revitalized cities by:

A) providing slave labor for manors.
B) founding many castles around which cities formed.
C) exploring new territory where new cities were founded.
D) founding manufacturing centers for the production of ships and arms.
E) returning large amounts of gold and silver coin to the markets of medieval Europe.