The Coase theorem suggests that private markets may not be able to solve the problem of externalities

A、ifthegovernmentdoesnotbecomeinvolvedintheprocess.;
B、whenthenumberofinterestedpartiesislargeandbargainingcostsarehigh.;
C、ifthefirminthemarketisamonopoly.;
D、ifsomepeoplebenefitfromtheexternality.