You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You create a custom Web user control named SharedControl. The control will be compiled as a library.  You write the following code segment for the SharedControl control： 01 protected override void OnInit（EventArgs e）   02 {   03   base.OnInit（e）；   04 ►  05 }    All the master pages in the ASP.NET application contain the following directive. <%@ Master Language="C#" EnableViewState="false" %>    You need to ensure that the state of the SharedControl control can persist on the pages that reference a master page.  Which code segment should you insert at line 04？（）

• A、Page.RegisterRequiresPostBack(this); 
• B、Page.RegisterRequiresControlState(this); 
• C、Page.UnregisterRequiresControlState(this); 
• D、Page.RegisterStartupScript("SharedControl","server");