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