What is the primary function of Address Resolution Protocol (ARP)?

The primary function of Address Resolution Protocol (ARP) is to translate IP addresses into MAC addresses. In a local area network (LAN), devices communicate using MAC addresses at the Data Link Layer, but higher-layer protocols such as IP operate using logical addresses known as IP addresses. When a device wants to send a packet to another device on the same LAN, it first identifies the IP address of the target device. However, to actually send the data frames, it needs to know the corresponding MAC address. ARP resolves this discrepancy by broadcasting an ARP request on the network, asking which device has the specified IP address. The device with the matching IP address then responds with its MAC address, enabling the sending device to encapsulate the packet with the correct MAC address for delivery on the network.

This makes ARP essential for enabling communication within a local network, as it ensures that devices can find each other irrespective of the addressing layers they operate on. The other options, while they relate to networking aspects, do not describe ARP's specific functionality. For instance, ARP does not manage IP addresses directly, monitor network security, or optimize data transfer; instead, its focus is solely on translating IP addresses to MAC addresses to facilitate communication within a given network segment