You are developing a Windows Presentation Foundation (WPF) application.
You are implementing a test strategy for the application.
You need to ensure that the test class can repeat user input.
From which base class should the test class inherit?（）

A. Add a FlowDocumentReader control to the design surface. Then create a FlowDocument control.
B. Add a DocumentViewer control to the design surface. Then create a FixedDocument control.
C. Add a WebBrowser control to the design surface. Then use the Navigate method to navigate the URI object.
D. Add a ContentControl control to the design surface. Then reference a WebClient object to return an HTML string.

A.
B.
C.
D.

A. Use a custom action. 
B. Set the MinVersion property to .NET Framework 4.
C. Set the Version property of Windows Installer to .NET Framework 4.
D. Set the Version property of the Launch Condition to .NET Framework 4.