The correct answer is C.
OBJ-1.6: There are several types of DNS records, including A, AAAA, CNAME, PTR, SVR, and TXT. PTR records are used for the Reverse DNS (Domain Name System) lookup. Using the IP address, you can get the associated domain/hostname. An A record should exist for every PTR record. Time to live (TTL) or hop limit is a mechanism which limits the lifespan or lifetime of data in a computer or network. The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol networks for automatically assigning IP addresses and other communication parameters to devices connected to the network using a client-server architecture. The Lightweight Directory Access Protocol (LDAP) is an open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed directory information services over an Internet Protocol network.