Economists generally believe that rent control is

A、anefficientandfairwaytohelpthepoor.;
B、inefficientbutthebestavailablemeansofsolvingaserioussocialproblem.;
C、ahighlyinefficientwaytohelpthepoorraisetheirstandardofliving.;
D、anefficientwaytoallocatehousing,butnotagoodwaytohelpthepoor.