After refreshing a zone, what should be ensured about the records?

After refreshing a zone, ensuring that the records are signed is crucial for maintaining the security and integrity of the DNS data. Signing DNS records involves the use of DNSSEC (Domain Name System Security Extensions), which provides a way to ensure that the records have not been altered and are coming from a legitimate source. This verification helps protect against various types of attacks, such as spoofing and cache poisoning, by allowing resolvers to authenticate the data they receive.

In the context of a DNS zone, signing the records ensures that clients querying the DNS can trust the information returned. This is especially important for zones that are critical to an organization's operations or that handle sensitive data. A signed zone establishes a chain of trust, offering an additional layer of security beyond simply having the data present.

The other choices do not align with the necessary actions relating to records after a zone refresh. Records being deleted is not a standard practice after a refresh, as the aim is to keep them updated. Transfer of records typically refers to zone transfer operations between primary and secondary DNS servers, which is not directly related to the routine refreshing process. Caching is a function of DNS resolvers or servers to improve lookup speed, but it doesn't pertain to the action of ensuring that records are properly