Answer:
c.Update DNS records dynamically for DHCP clients that don't request updates.
Step-by-step explanation:
A DNS server is a computer server that contains a database of public IP addresses and their associated host names, and in most cases serves to resolve, or translate, those names to IP addresses as requested.
A DHCP Server is a network server that automatically provides and assigns IP addresses, default gateways and other network parameters to client devices.
Dynamic DNS is a method of automatically updating a name server in the Domain Name Server, often in real time.