Answer:
a. Internet
Step-by-step explanation:
The internet is essentially the world’s largest computer network, linking hundreds of thousands of smaller networks and operating under a common set of rules for communication.
An extranet is a controlled private network that allows access to partners, vendors and suppliers or an authorized set of customers.
Cloud based networking is referred to the network communication and inter-connectivity between IT resources /application within a cloud computing infrastructure
An intranet is a computer network for sharing corporate information, collaboration tools, operational systems, and other computing services only within an organization, and to the exclusion of access by outsiders to the organization