单项选择题
设L是从点(0,0)沿y=1-|x-1|至点(2,0)的折线段,则曲线积分-ydx+rdy等于()
A.0 B.-1 C.2 D.-2
A.-8 B.8 C.0 D.20
A.2(ea-1) B.(πa/4)ea C.2(ea-1)+(πa/4)ea D.(1/2)(ea-1)+πaea