I have 3 classes in C#:

classclass Folder
{
    int Id { get; set; }
    List<File> files { get; set;}
}

class File
{
    int Id { get; set; }
    Author author { get; set; }
}

class Author
{
    int Id { get; set; }
    string Name { get; set; }
} 

I have a list of Folder items (List):

var folders = getAllFolders();

How can I use Linq to return a list of Folders from the list when i only know the Author id of the files?

I need the list to contain all folders where a given Author has created a file!

Thanks