You are designing a Windows Presentation Foundation (WPF) application by using Microsoft .NET Framework 4 and Microsoft Visual Studio 2010. You need to ensure that the following requirements are met: All UI elements are labeled. All property values are exposed. Keyboard navigation contains tab stops for all controls. The application functions on high contrast displays. Which testing strategy should you recommend?

A.
Stress testing

B.
Stability testing

C.
Usability testing

D.
Accessibility testing