Given the following Bash code snippet: Which of the following would be achieved?

User enumeration typically involves attempting to guess valid usernames, often through authentication mechanisms, not by using `wget` to download a specific file.

A directory brute-force attack involves systematically trying to discover hidden directories or files on a web server, which is not the function of a single `wget` command targeting a known file.

A port scan involves checking for open ports on a target system, usually with tools like Nmap, and is unrelated to downloading a file using `wget`.

The `wget` command is a command-line utility used for retrieving content from web servers. The `-O output.txt` option specifies that the downloaded content from `http://example.com/file.zip` should be saved to a local file named `output.txt`. Therefore, this command directly performs a file download.