How many collision domains are present in this network?

Refer to the exhibit.

All devices attached to the network are shown. How many collision domains are present in this
network?

A.
2

B.
3

C.
6

D.
9

E.
15

Explanation:
A switch uses a separate collision domain for each port so there are a total of 9 for each device
shown. In addition to this, the switch to switch connections (3) are a separate collision domain.
Finally, we add the switch to router connections (2) and the router to router connection (1) for a
total of 15.