[单项选择题] 以下程序运行后，单击命令按钮，窗体显示的结果是 ______。 Private Function p1(x As Integer，y As Integel，z As Integer)

[单项选择题] 以下程序运行后，单击命令按钮，窗体显示的结果是 ______。

Private Function p1(x As Integer，y As Integel，z As Integer)

p1=2*x+y+3*z

End Function

Private Function p2(x As Integer，y As Integer，z As Integer)

p2=p1(2，y，x)+x

End Function

Private SubCommandl_Click()

Dim a As Integer

Dim b As Integer

Dim c As Integer

a=2:b=3:c=4

Print p2(c，b，

A．

End SubA) 19

B．21

C．22

D．23