AgEism is DiFFErEnt From othEr "isms", BECAusE oF All thE Following rEAsons ExCEpt thAt______.
A．it is BAsED upon thE ConstAnt AgE ClAssiFiCAtion
B．thE ConCEpt oF AgEDnEss is ChAnging grADuAlly
C．onE is ExpEriEnCing thE Aging proCEss onEsElF
D．AgE ClAssiFiCAtion rEmAins thE sAmE For mAny yEArs