定语从句：He was very rude to the Customs officer,----- of course

定语从句：He was very rude to the Customs officer,_____ of course made things even worse.
A.who
B.whom
C.what
D.which
如果引导词是指代前面的句子,句中不是有两个谓语了吗?一个是was,一个是made!