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 Function Private Function SecProc(x As Integer，y As Integer，z As Integer) SecProc=FirProc(z，x，y)+x End Function Private Sub Command1_Click() Dim a As Integer Dim b As Integer Dim C As Integer a=2 b = 3 c = 4 Print SecProc(c，b，a) End Sub

A．21

B．19

C．17

D．34