Answer :
All options except 'd) example.com' are examples of subdomains in DNS. A subdomain organizes different sections or services of a website under the main domain. Domain name endings such as .com or .edu represent the type of website and its reliability. Therefore the correct answer is option a) mail. example. com, b) www. example. com, c) blog. example. com.
In the Domain Name System (DNS), a subdomain is a subdivision of a larger domain and it's used to organize different sections of a website or to signify a different service provided under the main domain. Examples of subdomains include addresses like mail.example.com, www.example.com, and blog.example.com. These subdomains precede the primary domain, which in these examples is example.com.
Domain name endings, also known as top-level domains (TLDs), such as .com, .edu, and .org, follow the primary domain and are essential in identifying the type of website and can indicate the reliability or purpose of the site. For example, .gov domains are typically used by government agencies, while .edu indicates an educational institution.
The correct answer to the student's question is that all the options provided, mail.example.com, www.example.com, and blog.example.com, are examples of subdomains, whereas example.com is the main domain.
