whiCh oF thE Following is not right ACCorDing to thE pAssAgE
A．somEthing CAn BE DonE to kEEp our ComputErs sAFE.
B．EvEn An E-mAil AttAChmEnt Coming From A FriEnD mAy not BE sAFE to opEn.
C．wE shoulD not usE our ComputErs to DEFEnD oursElvEs From virusEs.
D．Anti-virus soFtwArE mADE somE yEArs Ago is hArD to protECt toDAy's ComputErs.