I think it is A. People began using tools
Answer:
Educated, skilled, and affluent workers have received the benefits of economic growth during the past quarter century
Explanation:
The group of. people who have received the benefits of economic growth during the past quarter-century are the "Educated, skilled, and affluent workers have received the benefits of economic growth during the past quarter-century."
This is evident in the fact that this category of people tends to get more and high paying jobs. They are most sought after in the socio-economic space.
For example, most of the time Educated, skilled, and affluent workers earn more than other people like artisans with little or no educations
