Question:You are creating an ASP.NET Web site.
The site has a master page named Custom.master.
The code-behind file for Custom.master contains the following code segment.
public partial class CustomMaster : MasterPage
{
    public string Region
    {
        get; set;
    }
    protected void Page_Load(object sender, EventArgs e)
    {
    }
}
You create a new ASP.NET page and specify Custom.master as its master page.
You add a Label control named lblRegion to the new page.
You need to display the value of the master page's Region property in lblRegion.
What should you do? 
A Add the following code segment to the Page_Load method of the page code-behind file.
CustomMaster custom = this.Parent as CustomMaster;
lblRegion.Text = custom.Region; 
B Add the following code segment to the Page_Load method of the page code-behind file.
CustomMaster custom = this.Master as CustomMaster;
lblRegion.Text = custom.Region; 
C Add the following code segment to the Page_Load method of the Custom.Master.cs code-behind file.
Label lblRegion = Page.FindControl("lblRegion") as Label;
lblRegion.Text = this.Region; 
D Add the following code segment to the Page_Load method of the Custom.Master.cs code-behind file.
Label lblRegion = Master.FindControl("lblRegion") as Label;
lblRegion.Text = this.Region;