下面程序：Private Sub Form_Click（)Dim x，y，z As Integerx＝5y＝7z＝0Call P1（x，y，z)Print Str（z)En

下面程序：

Private Sub Form_Click()

Dim x，y，z As Integer

x＝5

y＝7

z＝0

Call P1(x，y，z)

Print Str(z)

End Sub

Sub P1(ByVal a As Integer, ByVal b As Integer, c As integer)

c＝a＋b

End Sub

运行后的输出结果为

A．0

B．12

C．Str(z)

D．显示错误信息