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