单项选择题

A.=0.2*70+0.2*75+0.6*55
B.=0.2*B3+0.2*C3+0.6*D3
C.=sum(0.2*B3:0.2*C3:0.6*D3)
D.=0.2*$B$3+0.2*$C$3+0.6*$D$3