单项选择题

单击命令按钮时,下列程序的执行结果是 Private Sub Command1_Click()   BT 4 End Sub Private Sub BT(x As Integer)   x=x*2+1   If x<6 Then     Call BT(x)   End If   x=x*2   Print x; End Sub

A.15
B.16
C.17
D.18