You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You create a page that contains the following control：       You write the following code segment in the code-behind file for the page：   void LoadDate（object sender， EventArgs e） {   if （IsPostBack） {   calBegin.SelectedDate = （DateTime）ViewState["date"]；   }  }    void SaveDate（object sender， EventArgs e） { ViewState["date"] = calBegin.SelectedDate；   }   You need to ensure that the calBegin Calendar control maintains the selected date.  Which code segment should you insert in the constructor of the page？（）

• A、A
• B、B
• C、C
• D、D