A junior Linux administrator needs to create 16 empty files quickly that will contain sales information for each quarter for the past four years. Which of the following commands will meet this…

The `touch` command combined with brace expansion `{{2015,2016,2017,2018}}.{{q1,q2,q3,q4}}` generates all combinations of years and quarters, creating 16 distinct filenames like `2015.q1`, `2015.q2`, etc. This allows for the efficient creation of all required empty files with a single command.

Square brackets `[]` are used for character ranges or sets in shell globbing, not for generating a Cartesian product of strings for file creation as required here.

Backticks `` ` `` are used for command substitution, executing an enclosed command and replacing it with its output, which is not applicable for generating multiple filenames.

While double braces indicate brace expansion, using dots `.` instead of commas `,` within the braces `{{2015.2016...}}` does not create separate elements for expansion; it treats the entire string as a single literal part or forms an invalid pattern.