Q.In which topology is every computer connected by its own separate cable to a central hub or switch?
(A) Bus topology
(B) Ring topology
(C) Star topology
(D) Mesh topology

Each topology has a distinctive shape; the one built around a single central device is named after the shape it makes.

A bus uses one shared backbone cable, a ring forms a closed loop, and a mesh connects every node to every other node.

Section d describes the network topologies. In a star topology, every computer is connected by its own separate cable to a central device — a hub or switch — through which all data passes. This is why one cable fault affects only one computer, and it is the most common topology in modern LANs. So option (C) is correct.

The other layouts are different: a bus topology (A) connects all computers to a single shared backbone cable; a ring topology (B) joins the computers in a closed loop; and a mesh topology (D) connects every computer directly to every other computer. Only the star is built around a single central hub or switch.

Do not confuse the star with the bus. In a bus, all computers share one backbone cable; in a star, each computer has its own cable to a central device. The phrase 'central hub or switch' is the clue for the star.