Regular Expression for Matching Any Character

A regular expression that matches any character is '.' (dot). It matches any character except for newline characters.

Here's why the other options are incorrect:

• \S: Matches any non-whitespace character.
• \w: Matches any alphanumeric character, including underscores.
• [a-zA-Z]: Matches any single character that is a letter from 'a' to 'z' or 'A' to 'Z'.