The correct answer is D. *
A wildcard is a special character that can be used to represent one or more characters in a file name. The asterisk (*) wildcard can be used to match any number of characters, including none. For example, the command ls *.txt
will list all files in the current directory that end in .txt, even if the file name does not contain any other characters.
The other options are not wildcards. Option A, [ijk]
, is a character class that matches any one of the characters i, j, or k. Option B, [!ijk]
, is a negated character class that matches any character that is not i, j, or k. Option C, ?, is a single-character wildcard that matches any single character.
I hope this helps! Let me know if you have any other questions.