单项选择题
设L是由圆周x2+y2=a2,直线x=y,及x轴在第一象限中所围成的图形的边界,则的值是:()
A.2(ea-1) B.(πa/4)ea C.2(ea-1)+(πa/4)ea D.(1/2)(ea-1)+πaea
A.- B.1-2 C.1+ D.-1+