You create a Web page named TestPage.aspx and a user control named TestUserControl.ascx. TestPage.aspx uses TestUserControl.ascx as shown in the following line of code. On TestUserControl.ascx， you need to add a read-only member named CityName to return the value "New York". You also must add code to TestPage.aspx to read this value. Which two actions should you perform？（） A. Add the following line of code to the TestUserControl.ascx.cs code-behind file. public string CityName { get { return "New York"; } } B. Add the following line of code to the TestUserControl.ascx.cs code-behind file. protected readonly string CityName = "New York"; C. Add the following code segment to the TestPage.aspx.cs code-behind file. protected void Page_Load(object sender, EventArgs e) { string s = testControl.CityName; } D. Add the following code segment to the TestPage.aspx.cs code-behind file. protected void Page_Load(object sender, EventArgs e) { string s = testControl.Attributes["CityName"]; }