You should select Router to connect the two groups of computers so that data communication can occur.
Step-by-step explanation:
Routers are essential for the communication between two or more computers that are connected to a network. The primary function of routers is making connection between various networks and the data packets will be forwarded to the computers of same network of different networks.
It is a layer 3 device. This because the data that is contained in the layer 3 IP packet that contains the IP address of the destination to which the packet should be forwarded plays a very important role in making decisions related to the data packets forwarding. Thus a Router must be selected for connecting two groups of computer for data transfer and communication.