Which first generation network topology used a single cable that connected all the computers in a line?

Bus topology

Explanation:

Network topology is a descriptive view or shape pattern of network devices arrangement on a network. It does not necessarily describe how packets are transmitted. They are different types of network topology, they are star, bus, token - ring, mesh.

In star topology, each computer on the network is connected to a central device, while all the computers in bus network is connected to a network line. In mesh topology, all computers are connected to each other, while computers are arranged in circles in a token-ring topology.