阅读下面的程序段：
For i=1 To 3
For j=i To 3
For k= 1 To 3
a=a+i
Next k
Next j
Next i
执行上面的3重循环后，a的值为

A．Abs(e^3+Lg(x)+L/Tg(y) )
B．Abs(Exp(3)+Log(x)/Log(10)+Atn(y))
C．Abs(Exp(3)+Log(x)+Atn(y) )
D．Abs(Exp(3)+Log(x)+1/Atn(y) )