has been bought
have been bought
was bought
were bought
本题考查主谓一致和一般过去时。根据句中时间状语a week ago可知要用一般过去时态。当主语后面由as well as连接几个名词或短语时，谓语动词要与最前面的主语保持一致，名词furniture为不可数名词，所以谓语动词用单数形式。“家具”和“购买”是被动关系，故选C。
句意：史密斯一家一周前为他们的新房子买了许多新的木制家具和一些最新的家用电器。
