题目内容：
You are developing a Windows Presentation Foundation (WPF) application. All of the application styles are in the file name Themes.dllYou have the followiing markup segment.BlueBackground is defined in a XAML file named BlueTheme.xaml. The XAML markup is compiled into the Themes.dll file.You need to ensure that the XAML file is referenced so that the application can apply the settings in the BlueBackground style.（）
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