---Thebookisn'teasyforJacktounderstand,isit?---________．Hisforeignla

---The book isn't easy for Jack to understand, is it?---________．His foreign language is far better than expecteD．A.No, it isn'tB.I'm afraid notC.I don't think soD.Yes, it is

D解析回答该反意疑问句相当于回答Is it easy for Jack to understand？答语根据实际，前后要一致．根据语境：His foreign language is far better than expected．说明Jack的英语非常棒，这本书对于Jack应当是简单的．

对的，就是这个意思