An office network consists of one two-port router connected to a 12-port switch. A four-port hub is also connected to the switch. On this particular network, which of the following is the number of collision domain that exist?

An office network consists of one two-port router connected to a 12-port switch. A four-port hub is also connected to the switch. On this particular network, which of the following is the number of collision domain that exist?
A . 3
B . 12
C . 13
D . 14
E . 15

Answer: D