Final answer:
CARP (Common Address Redundancy Protocol) is the protocol that focuses on providing high availability by allowing multiple hosts to share IP addresses, ensuring continuous network service availability. the correct option is CARP.
Step-by-step explanation:
The protocol focused on providing high availability is CARP (Common Address Redundancy Protocol).
CARP is designed to allow multiple hosts on the same local network to share a set of IP addresses. Its primary purpose is to ensure that if one node fails, another can take over seamlessly, thus providing high availability for network services. Other protocols like IMAP (Internet Message Access Protocol), DHCP (Dynamic Host Configuration Protocol), and RARP (Reverse Address Resolution Protocol) have different purposes. IMAP is used for email retrieval, DHCP for dynamic IP address allocation, and RARP for mapping a physical machine address to an IP address.
ARP is used to map an IP address to a physical (MAC) address on a local network. It allows devices to communicate and send data packets to each other. By maintaining an ARP cache, devices can quickly retrieve the MAC address of another device, ensuring the availability of network communication.