A host needs to determine the Media Access Control (MAC) address of another host on the same local network using the Address Resolution Protocol (ARP). Which statement correctly describes how the ARP request is transmitted?

### Why this is right - **A** is true: an ARP request uses the broadcast MAC address `FF:FF:FF:FF:FF:FF` because the requester does not yet know the target's MAC address. - **B** is true: a switch forwards a broadcast frame to the other ports in the same broadcast domain, not back through the incoming port. - **C** is true: the host that owns the requested IPv4 address can reply with its own MAC address. ### The concept Address Resolution Protocol (ARP) connects an IPv4 address to a MAC address on a local network. The request asks which device owns a particular IPv4 address and includes the sender's own addressing information. The broadcast reaches local devices, but only the device with the requested IPv4 address needs to provide the matching MAC address. The switch also learns source MAC addresses from the frames it receives. ARP's broadcast approach is simple, but it creates traffic for devices that are not the intended target and can be inefficient or insecure. ### The other options - **D. The request is sent as a unicast frame only to the target host's MAC address, which the requester already knows.**: This describes a situation where the requester already knows the MAC address, which defeats the purpose of ARP address resolution. The request is broadcast so the target can be found. ### Terms - **ARP**: Address Resolution Protocol. It finds the MAC address associated with an IPv4 address on a local network. - **MAC**: Media Access Control. The address used for local link delivery. - **IPv4**: Internet Protocol version 4. The version of Internet Protocol that uses 32-bit addresses. - **Broadcast**: Delivery of a frame to all devices in the relevant broadcast domain. - **Broadcast domain**: The group of ports and devices that receive a given Layer 2 broadcast. - **Switch**: A device that forwards frames using MAC addresses. - **Unicast**: Delivery from one sender to one identified receiver. - **Frame**: A unit of data sent over a local link. ### Remember ARP broadcasts the question because the sender does not yet know the target MAC address.