请阅读Passage2，完成第小题。 Passage2 Thatexperiencesinfluencesubsequentbehaviorisevidenceofanobviousbutneverthelessremarkableactivitycalledremembering.Learningcouldnotoccurwithoutthefunctionpopularlynamedmemory.Constantpracticehassuchaneffectonmemoryastoleadtoskillfulperformanceonthepiano,torecitationofapoem,andeventoreadingandunderstandingthesewords.So-calledintelligentbehaviordemandsmemory,rememberingbeingaprimaryrequirementforreasoning.Theabilitytosolveanyproblemoreventorecognizethataproblemexistsdependsonmemory. Typically,thedecisiontocrossastreetisbasedonrememberingmanyearlierexperiences. Practice(orreview)tendstobuildandmaintainmemoryforataskorforanylearnedmaterial. Overaperiodofnopracticewhathasbeenlearnedtendstobeforgotten;andtheadaptiveconsequencesmaynotseemobvious.Yet,dramaticinstancesofsuddenforgettingcanbeseentobeadaptive.Inthissense,theabilitytoforgetcanbeinterpretedtohavesurvivedthroughaprocessofnaturalselectioninanimals.Indeed,whenone'smemoryofanemotionallypainfulexperienceleadstoseriousanxiety,forgettingmayproducerelief.Nevertheless,anevolutionaryinterpretationmightmakeitdifficulttounderstandhowthecommonlygradualprocessofforgettingsurvivednaturalselection. Inthinkingabouttheevolutionofmemorytogetherwithallitspossibleaspects,itishelpfultoconsiderwhatwouldhappenifmemoriesfailedtofade.Forgettingclearlyaidsorientationintime,sinceoldmemoriesweakenandthenewtendtostandout,providingcluesforinferringduration. Withoutforgetting,adaptiveabilitywouldsuffer,forexample,learnedbehaviorthatmighthavebeencorrectadecadeagomaynolongerbe.Casesarerecordedofpeoplewho(byordinarystandards)forgotsolittlethattheireverydayactivitieswerefullofconfusion.Thisforgettingseemstoservethesurvivaloftheindividualandthespecies. Anotherlineofthoughtassumesamemorystoragesystemoflimitedcapacitythatprovidesadaptiveflexibilityspecificallythroughforgetting.Inthisview,continualadjustmentsaremadebetweenlearningormemorystorage(input)andforgetting(output).Indeed,thereisevidencethattherateatwhichindividualsforgetisdirectlyrelatedtohowmuchtheyhavelearned.Suchdataoffersgrosssupportofcontemporarymodelsofmemorythatassumeaninput-outputbalance. Fromtheevolutionarypointofview,__________. 查看材料
A.sudden forgetting may bring about adaptive consequences
B.forgetting for lack of practice tends to be obviously inadaptive
C.if a person gets very forgetful all of a sudden, he must be very adaptive
D.forgetting is an indication of an individual's adaptability
正确答案是A