Collapse all #regions only(!) in C# (Visual Studio)

Question

There\'s a number of keyboard shortcuts and menu commands to automatically expand or collapse all foldables in the current document. Ctrl+M, Ctrl

Answer 1

in Visual Studio 2017 I have to activate 'Collapse #regions when collapsing to definitions' in

Tools -> Options -> Text Editor -> C# -> Advanced

explicitly to collapse all when pressing Ctrl+M+O