Which of the Following Does Not Accurately Describe a Medieval

Which of the following does not accurately describe a medieval castle?

A) Castles were most often built on higher sites to better repulse attacks.
B) With the development of new military and assault methods, castles became primarily private residences.
C) Stone castles became prevalent as quarrying methods developed.
D) Castles appeared in Europe after the period of the Crusades.
E) The number of castles in an area signified the political decentralization of that area.