单击命令按钮时，下列程序代码的执行结果为( )。
Private Function FirProc(x As Integer,y As Integer,z As Integer)
　　　FirProc=2*x+y+3*z
End Funcfion
Private Function SecProc(x As Integer,y As Integer,z As Integer)
　　　SecProc=FirProc(z，x，y)+x
End Funcfion
Private Sub Command1_Click()
Dim a As Integer
Dim b As Integer
Dim c As Integer
a=2
b=3
c=4
Printf SecProc(c,b,a)
End Sub

A．21

B．19

C．17

D．34