Which of the following best describes a period cost?

A、Acostthatrelatestoatimeperiodwhichisdeductedasexpensesfortheperiodandisnotincludedintheinventoryvaluation.;
B、Acostthatcanbeeasilyallocatedtoaparticularperiod,withouttheneedforarbitraryapportionmentbetweenperiods.;
C、Acostthatisidentifiedwithaunitproducedduringtheperiod,andisincludedinthevalueofinventory.Thecostistreatedasanexpensefortheperiodwhentheinventoryisactuallysold.;
D、Acostthatisincurredregularlyeveryperiod,egeverymonthorquarter.