A.(600+80)×(1-30%)×1.2%=5.712(万元)
B.(600-50)×(1-30%)×1.2%=4.62(万元)
C.600×(1-30%)×1.2%=5.04(万元)
D.(600+80-50)×(1-30%)×1.2%=5.292(万元)