The best answer is A.
Information revolution is the development of technologies (such as computers, digital communication, microchips) in the second half of the 20th Century that led to the dramatic reduction in the cost of obtaining, processing, storing and transmitting information in all forms which include text, graphic, audio and video.
Creation of computers has been the main factor behind information explosion beginning with mainframe computers in the 1950s and 1960s, then mini-computers in the 1970s and 1980s and finally PCs in the 1980s to the 2000s.
