Assertion (A): Bus topology is based on a central node which acts as a hub.

Reasoning (R): Bus topology installation involves low cost.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

A is false but R is true.

Explanation
Bus topology is a multi-point configuration where several devices are connected to a main long cable, usually a coaxial cable, which acts as a backbone. This topology is cost-effective to install compared to other network topologies due to the simplicity of its design. Because there is only one communication line (the bus) and no additional networking hardware like switches or hubs needed, the overall setup cost is lower.