题目内容：
根据以下材料，回答题Billandhisfamilyhavebeenlivinginthesameoldbuildingforeightyears.Thelandlordalsolivesthere,andusuallyallthetenants(房客)getalongfairlywellwithoneanother.Recently,however,therehasbeenachangeintheirrelations.
Anice,quietold"coupleusedtolivethere,too.TheoldladywouldsometimesbringsomesmallcakesshemadetoBill'smother,whoinreturnwouldgivehersomemeatorhelpherwithshopping.
Unfortunately,theoldladydiedlastmonth.Asherhusbandcouldn'tlivealone,hisgrandsonmovedin.
Thegrandson,ayouthofabouttwenty,hasbecomeaproblemtoBill'sfamilybecauseheissonoisy,Bill'sfamily.memberswereusedtopeaceandquiet,buttheyouthlikestolistentohisradio
lateatnight.Sometimeshisfriendscameforavisit,andtheyalsomadealotofnoise.EveryoneinBill'sfamilyhasbeenbotheredbythenewcomerandgettingangry.
Bill'smotheroncepolitelyaskedtheoldmanifhewasabletosleepwellatnight,butitseemedthathedidn'tunderstandwhatshemeantandsoneverspoketohisgrandsonaboutit.Ifhedid,
thegrandsonapparentlydidn'tlisten,sincethingshavenotchangedany.EveryoneinBill'sfamilyagreesthatsomethinghastobedone,butnoonewantstohurttheoldman'sfeelingsor
causehimanyproblems.
Whatdoyouthinkshouldbedone?
Bill'sfamilygotangrywiththeirneighborbecause________. A．theoldladydied
B．ayoungmanmovedin
C．thegrandsonmadealotofnoise
D．theyoungmancouldnotlivealone
参考答案：
答案解析：