当Command1_Click事件发生时，窗体上显示的内容是 ______。 Private Sub Command1_Click() Dim a As Integer，b As Integer，c As Integer If a = 0 Then x = x-1 Else If b ＜＞ 0 Then x = 7 Else x=x+8 End If If c ＜＞ 0 Then x = x-3 Else x = 4 End If Print x End Sub

A．7

B．8

C．4

D．3