Final answer:
Yes, PC A and PC B can communicate without router R1 through a peer-to-peer network.
Step-by-step explanation:
Yes, PC A and PC B can communicate without router R1. This can be done through a direct connection known as a peer-to-peer network. In a peer-to-peer network, devices can communicate with each other by connecting to the same local area network (LAN) or using a Wi-Fi direct connection.
For example, if PC A and PC B are connected to the same Wi-Fi network, they can share files, printers, and other resources without the need for a router.
However, without a router, PC A and PC B will not be able to communicate with devices outside of their local network. In that case, they would need a router to connect to the internet or communicate with devices on other networks.