下列程序段的执行结果为( )。 Dim A(3,3) For M=1 To 3 For N=1 To 3 If N=M Or N=3-M+1 Then A(M, N)=1 Else A(M,N)=0 End If Next N Next M For M=1 To 3 For N=1 To 3 Print A(M,N) Next N Print Next M
                                                            
                                                                A.1  0  0
  0  1  0
  0  0  1
B.1  1  1
  1  1  1
  1  1  1
C.0  0  0
  0  0  0
  0  0  0
D.1  0  1
  0  1  0
  1  0  1