题目内容：
单击一次命令按钮，下列程序代码的执行结果为（ ）。Private Sub Command1_Click()
Dim a As Integer，b As Integer，C As Integer
a＝2：b＝3:c＝4
Print P2(c，b，a)
End Sub
Private Function P l(x As Integer，Y As Integer，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(z，x，y)+x
End Function A．21
B．19
C．17
D．34
参考答案：
答案解析：