A,前面否定后面反问用肯定,前面助动词是do,所以后面排除has,因为是he,所以相应第三人称单数does,所以选a
A前否后肯(当think,suppose的主语是I时,反意问句尾句跟宾语从句一致:因为说话者不可能自问的)(如果D改为has也可以的,因为这里的has是“有”的意思)如:He has a brother, doesn't he?(或hasn't he)He doesn't think you are right, does he?(think的主语是he)