The correct answer is answer C ("In the 1980s").
Computers started reaching homes and businesses on a bigger scale during the eighties. The difference was made when IBM brought to the market the revolutionary concept of a Personal Computer (PC), which for the first time allowed a single user to operate a computer. Before then, the user would give commands to a mainframe computer and a whole team would have process the request and operate the machine in order to bring results.
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