Which network devices will receive the ARP request sent by Host A in a default switch configuration?

In a default switch configuration, when Host A sends an ARP (Address Resolution Protocol) request, it is designed to discover the MAC address associated with a specific IP address on the local network. The switch operates at Layer 2 of the OSI model and uses a process called flooding to deliver the ARP request.

When Host A sends out the ARP request, the switch will indeed send the broadcast frame to all devices connected to that switch port. This means that the frame will reach all devices within the same broadcast domain, including Hosts B and C, as well as any other devices connected to the switch, such as Router R1, if it is within the same broadcast domain.

The ARP request typically asks: "Who has IP address X? Tell Host A." Since the request is broadcast, all devices that receive this request will check if they recognize the IP address in question. If the IP belongs to either Host B, Host C, or Router R1, they will respond with their MAC address.

Therefore, in this scenario, the correct response includes Hosts B and C, as well as Router R1, assuming Router R1 has an IP address in the same subnet as Host A. This makes option C correct,