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()
BT4
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