Answer:
b. intranet
Explanation:
An intranet is basically a computer network that cannot be accessed by the general public. Generally we think of intranets as local networks that are restricted to only a certain group of users, but some intranets are national or even international. The pentagon's intranet is accessed from all over the world.
The difference with the internet, is that anyone can access the internet, while an intranet is used by specific people.
