Answer:
d. 1990s
Step-by-step explanation:
The World Wide Web is a kind of friendly information system that uses hypertext, and since its creation has made Internet available for most people.
The Internet already existed quite before the World Wide Web: the first computer network was ARPANET (created in 1969), a project of the Advanced Research Projects Agency of the United States Department of Defense.
Further developments in computers' protocols (ways in which computers communicate with each other) resulted in a network of networks, or the Internet, in 1983.
Although the World Wide Web was a proposal first published on March 12, 1989, by Tim Berners-Lee of the European Nuclear Research Center (CERN) --this is why it is considered that the World Wide Web was created in 1989-- the idea came into life at the end of the year 1990, for the following reasons:
- After that proposal of 1989, Berners-Lee wrote another on May 1990, and in September 1990 he received support to develop those ideas.
- Some of the essential technologies needed to create the World Wide Web were already available by October 1990, that is, the HTTP (Hypertext Transfer Protocol), the HTML (Hypertext Markup Language) and the URI (Universal Resource Identifier), all considered been developed by Berners-Lee.
- On November 12, 1990, with the Belgian engineer Robert Cailliau, who was working in similar ideas, wrote a more formal proposal of such a system to share information across the CERN where they mentioned: "build a Hypertext project called WorldWideWeb" [Wikipedia, 2019].
Well, by the end of December 1990, in a NeXT computer, and after the creation of the first web server and the first web page browser, the first web site, running at CERN, appeared on December 20, 1990.
This idea was rapidly adopted outside the CERN in 1991 and, by the end of the 1990s, more than 130 million people could access the Internet using the World Wide Web technology.
In conclusion, the World Wide Web went live in the decade of 1990s: was a project, a proposal by the end of 1989 and started to work as a fast-adopted technology at the beginning, and throughout, the 1990s.