【单选题】

Questions 30 to 32 are based on the passage you have just hearD、 A．Kings and queens, princes and princesses, and lords and ladies built castles in order to get more lanD、

B．Around the outside of a castle, a moat was dug, which was often filled with water.
C．A、castle was built behind a thick and high stonewall, which was strong enough to stand the possible attack of enemies.
D．If a drawbridge was pulled up, there was no way for people to enter the castle.