in pArAgrAph 2, thE "impossiBly DiFFiCult ChAllEngE" proBABly rEFErs to _________.
A．AChiEving thE goAls stAtED in thE kyoto protoCol
B．ABiDing By thE rulEs lAiD Down in thE kyoto, protoCol
C．kEEping with AnD mAintAining thE spirit oF thE kyoto protoCol
D．AChiEving Emissions stAnDArD rEDuCtions in thE short spAn oF timE AllowED in thE kyoto protoCol