You use Microsoft .NET Framework 4 to create a Windows Forms application. 
You plan to use a Windows Presentation Foundation (WPF) control of the UserControl1 type hosted in an
ElementHost control named elementHost1. 
You write the following code segment. (Line numbers are included for reference only.)

You need to ensure that the application changes the background color of the hosted control when the background color of the form changes.  
Which code segment should you insert at line 05?（）

You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. 
You write the following code segment. (Line numbers are included for reference only.) 

the TextBox control is data-bound to an instance of the Contact class.  
You need to ensure that the Contact class contains a business rule to ensure that the ContactName property is not empty or NULL.
You also need to ensure that the TextBox control validates the input data. 
Which two actions should you perform?（）