Which of the following protocols is used by a host that knows its own MAC (Media Access Control) address to query a server for its own IP address?

RARP is the inverse of ARP - while ARP resolves a known IP address to a MAC address, RARP resolves a known MAC address to an IP address. A host (typically a diskless workstation) broadcasts its MAC address in a RARP request, and a RARP server responds with the corresponding IP assignment. This behavior is defined in RFC 903 and was an early mechanism for dynamic IP configuration before BOOTP and DHCP replaced it.

ARP (Address Resolution Protocol) resolves a known IP address to a MAC address, which is the opposite direction of the mapping described in the question.

DNS resolves human-readable hostnames to IP addresses and operates entirely at the application layer with no involvement in MAC-to-IP mapping.

Reverse DNS (RDNS) performs PTR record lookups to map IP addresses back to hostnames and has no mechanism involving MAC addresses.