You are designing Windows Presentation Foundation (WPF) applications by using Microsoft .NET Framework 4.

You need to maintain a common appearance and behavior across all applications in your company. You also need to ensure that the look and feel of the applications can be modified without recompiling them.

What should you create?

A.
a merged resource dictionary

B.
user controls in a shared assembly

C.
an instance of the System.Windows.Media.StyleSimulations class

D.
custom controls in a shared assembly