You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5.  You create a Web page that has a GridView control named GridView1. The GridView1 control displays the  | English | Chinese | Japan | Korean | - 88 - Test Information Co.， Ltd. All rights reserved. data from a database named Region and a table named Location.  You write the following code segment to populate the GridView1 control. （Line numbers are included for reference only.）  01 protected void Page_Load（object sender， EventArgs e）  02 {  03 string connstr；  04  05 SqlDependency.Start（connstr）；  06 using （SqlConnection connection =  07 new SqlConnection（connstr））  08 {  09 SqlCommand sqlcmd = new SqlCommand（）；  10 DateTime expires = DateTime.Now.AddMinutes（30）；  11 SqlCacheDependency dependency = new 12 SqlCacheDependency（"Region"， "Location"）；  13 Response.Cache.SetExpires（expires）；  14 Response.Cache.SetValidUntilExpires（true）；  15 Response.AddCacheDependency（dependency）；  16  17 sqlcmd.Connection = connection；  18 GridView1.DataSource = sqlcmd.ExecuteReader（）；  19 GridView1.DataBind（）；  20 } 21 }  You need to ensure that the proxy servers can cache the content of the GridView1 control. Which code segment should you insert at line 16？（）

• A、A
• B、B
• C、C
• D、D