Final answer:
A records and NS records are valid types of DNS records commonly used in the Domain Name System (DNS) to link domain names to IPs and specify DNS servers, respectively. Other options given are not standard types of DNS records.
Step-by-step explanation:
The question concerns the different types of DNS records. Among the options listed, the valid types of DNS records are: A, D, and F.
Other options such as 'B records', 'NF records', 'UDP records', 'DNSSEC records', and 'Root records' are not standard DNS record types. 'DNSSEC' relates to the DNS security extensions, but it is not a record type itself. Typically, you would see DNSSEC configuration details within DS, RRSIG, or other related records. There is also no such thing as 'Root records' in the context of DNS records; the 'root' usually refers to the root level of the DNS hierarchy.
A. A record is a valid type of DNS record. It stands for Address record and is used to map a domain name to an IP address. For example, if you want to access www.example.com, the A record will contain the IP address where the website is hosted.
D. NS record is also a valid type of DNS record. It stands for Name Server record and is used to delegate a domain to a set of name servers. These name servers then provide the IP addresses corresponding to the domain.
F. DNSSEC record is another valid type of DNS record. It stands for Domain Name System Security Extensions and is used to add an extra layer of security to DNS queries and responses. It helps prevent DNS attacks such as cache poisoning.