窗体中有文本框Text1、Text2和Text3。运行程序时,输入整数m和n(n>0),单击按钮Command1计算下列表达式的值: SUM=m+(m-1)/2+(m+2)/3+(m-3)/4+…+(m+(-1)n+1(n-1))/n在Text3给出结果,事件代码如下:Private Sub Command1_Click() Dim sum As Double m=Val(me!Text1) n=Val(me!Text2) sum=0 For k=1 to n sum=sum+(【 】)/k Next k Me!text3=sumEnd Sub程序【】处应填写的语句是:
A.m + IIf(k Mod 2 = 0, -k + 1, k - 1) B.m + IIf(k Mod 2 = 0, k - 1, -k + 1) C.IIf(k Mod 2 = 1, m - k + 1, m + k - 1) D.IIf(k Mod 2 < 0, m + k - 1, -m + k - 1)