thE golD stAnDArD is ______.
A．thE AvErAgE priCE oF golD on thE worlD mArkEt
B．A BAsis For DEtErmining thE vAluE oF CurrEnCy
C．thE Amount oF golD rEquirED By A nAtion BEForE its CurrEnCy CAn BE mADE ConvErtiBlE
D．A mEAns oF DEtErmining thE quAlity oF golD