Over the Past Century, Technical Advances Have Led to Machines

Over the past century, technical advances have led to machines that have replaced workers in many occupations. What impact has this had in labor markets?

A) In the long run, unemployment rates have not increased. As jobs are lost in one industry, new opportunities seem to develop in other industries.
B) In the long run, unemployment rates have increased. As workers are replaced by machines, few jobs are available.
C) Labor markets increasingly need more low-skill workers and fewer high-skill workers.
D) Automation has reduced the number of jobs requiring reasoning and judgment.