Four friends, Edwin, Fred, Gary and Howard, were playing together when one of them broke a vase.  The teacher asked: "Who is the culprit?"  Both Edwin and Howard said, "Not me."  Fred said, "Howard broke the vase."  Gary said, "Fred is the culprit."  If only one of four boys was lying,  broke the vase. 
选项为:A:Edwin  B:Fred  C:Gary  D:Howard  请回答其中一个选项.