What characterizes an authoritative DNS server?

An authoritative DNS server is characterized by its role in holding complete knowledge of domains and their corresponding IP addresses. This means that it has the definitive information about the domain names it manages and can provide accurate responses to queries from DNS resolvers regarding those domains. When a DNS resolver queries an authoritative server, it receives answers that are considered trusted and authoritative because they come directly from the server that has the authoritative data for that domain.

In contrast, options such as distributing IP addresses to clients pertain to DHCP (Dynamic Host Configuration Protocol) functionality rather than DNS. The role of connecting users to the internet involves routers and gateways that manage network traffic rather than DNS servers specifically. Lastly, managing email forwarding is typically handled by mail servers, not by authoritative DNS servers, although DNS does play a part in pointing to the correct mail servers through MX (Mail Exchange) records. Thus, the correct answer underscores the specific responsibility of an authoritative DNS server in relation to domain name resolution.