问题: WhichofthefollowingstatementsDOESNOTanswerthequestion"Whatcausedthe"life-savingeffect"tooccurintheearly1990s?"
A: Thereweremorecellphoneusersduringthatperiod.
B:Thenumberofcellphoneusersreachedabout100million.
C:Morecellphoneswereusedtocall911whenaccidentsoccurred.
D:ellphonesenabledpeopletohavequickaccessto911services.
