サーバー管理者は、Webドメインの所有権を確認するために、会社のDNSサーバーにレコードを追加する必要があります。管理者はレコードの名前と値を知っています。管理者は、DNSサーバーにレコードを追加するために、次のどのレコードタイプを使用すべきでしょうか?
正解:A
To verify ownership of a domain, providers commonly require adding a TXT record to DNS containing a specific validation token (a name/value pair). A TXT (text) record is designed to store arbitrary text data associated with a domain or hostname, which makes it ideal for domain verification workflows used by certificate authorities, email security (SPF/DKIM/DMARC-related entries), and third-party services that need proof of administrative control over DNS. This fits Network+ DNS objectives that cover common record types and their practical purposes in real deployments.
An A record maps a hostname to an IPv4 address and is used for name-to-address resolution, not ownership verification. A PTR record provides reverse DNS mapping (IP address to hostname) and is stored in reverse lookup zones, not typically used for validating web domain ownership. A CNAME record creates an alias from one hostname to another canonical hostname; while sometimes used in service integrations, the classic
"record name + token value" ownership verification is most directly and universally satisfied by a TXT record. Therefore, TXT is the correct choice given the requirement and the provided record name and value.