Using a switch rather than a hub on a traditional ethernet lan segment
a. essentially creates a logical bus topology out of a the more traditional and slower star network.
b. essentially creates a logical star topology out of the more traditional and slower bus network.

essentially creates a logical star topology out of the more traditional and slower bus network.

Explanation:

The bus topology is a kind of ethernet connection where one cable known as the backbone is responsible for all the connections, therefore a failure at any point results in the failure of the whole system. Whereas a star topology which is commonly used connect several device in a network to one central device.

The hub is outdated so also is the bus network, while the star and the switch are in common use now.

answer; its the top layer;

answer; certification; plz check first, i believe this is correct. good luck;