资料题：In which of the positions marked [1], [2],[3] and [4] does the following sentence best belong?“Don’t hesitate as this offer is valid only until April 1st.”

Trade Explorer Magazine1030 Newbury Street, Philadelphia, PAMarch 12Lance Hughes Marketing Manager E-book StationDear Mr. Hughes,Our records show that you haven’t published an advertisement with Trade Explorer Magazine for the past six months. — [1] —. We sincerely value the business of customers like yourself and would like to offer you a special promotion. — [2] —. In the past, you have taken out several full-page advertisements in our monthly publication. We would like to offer you the chance to post a full-page advertisement at half the standard rate in our next four issues. If you accept our proposal, we will also provide you with a free button advertisement on our Web site. — [3]—.To place an advertisement, please fill out the enclosed form and mail it back to us. —[4] —. Should you need any assistance with the layout or design of your advertisement, we are also willing to accommodate you in that regard. You may contact our business representative, Juliet Abbot, at 555-0306 for additional information.We hope you will find our offer beneficial and cost-effective.Sincerely yours,Liza Huntington Managing Editor Trade Explorer Magazine