33. 執行下列程式後，訊息交談窗會顯示幾個 "*" 號？ Dim I As Integer Dim star As String star = "" I = 20 Do 　　star = star + "*" 　　I = I - 6 Loop While I >= 1 MsgBox(star) (A)6 (B)5 (C)4 (D)3