The correct answer is: C. Test Top-Level Domains (tTLD)
A top-level domain (TLD) is the last part of a domain name, such as .com, .net, or .org. TLDs are divided into three categories: generic top-level domains (gTLDs), sponsored top-level domains (sTLDs), and test top-level domains (tTLDs).
Generic top-level domains are the most common type of TLD. They are used for general purposes, such as .com for commercial websites, .net for network-related websites, and .org for non-profit organizations.
Sponsored top-level domains are a type of TLD that is sponsored by a specific organization. They are used for specific purposes, such as .edu for educational institutions, .gov for government websites, and .mil for military websites.
Test top-level domains are a type of TLD that is used for testing new domain name technologies. They are not intended for public use.
The .test domain name is a test top-level domain. It was created in 2014 by the Internet Corporation for Assigned Names and Numbers (ICANN) to allow people to test new domain name technologies. The .test domain name is not intended for public use.