D.txt -

: Instructors use it to show how loops can iterate through a list of files (e.g., for file in a.txt b.txt c.txt d.txt; do cp "$file" backup/; done ).

Manage small groups of related files with the argument list : r/vim : Instructors use it to show how loops

Since d.txt is a plain text file, it is the simplest type of digital document to create and edit. do cp "$file" backup/