流转税类以流转额为课税对象，下列属于流转税类的（）。

A.增值税

B.个人所得税

C.资源税

D.消费税

E.营业税

His writing is so confusing that it's difficult to make out          it is that he is trying to express. [ ]

A. that      

B. how    

C. who    

D. what