Final answer:
ARP request is broadcast to all devices on the network, while ARP reply is sent directly (unicast) from the target device to the host that originated the request.
Step-by-step explanation:
The Address Resolution Protocol (ARP) is a fundamental part of IP networking and is used to map IP network addresses to the hardware addresses used by a data link protocol. The correct statement regarding ARP is: a. ARP request is broadcast, and ARP reply is unicast. When a host wants to communicate with another host on the local network and does not know its physical address, an ARP request is broadcast to all devices on the network. The target device, recognizing its IP address in the request, will send an ARP reply directly to the requesting host, hence the reply is unicast.