Describe, respectively, the pioneering industrial practices implemented by Andrew Carnegie and John D. Rockefeller during the late nineteenth century.

The correct answer to this open question is the following.

Although there are no options attached, we can say the following.

The industrial practices implemented by Andrew Carnegie and John D. Rockefeller during the late nineteenth century were business practices that supported the creation of monopolies in the United States.

These wealthy people received the name of the Robber Barons.

The Robber Barons were wealthy owners of the American Industries during the Gilde Edge. Two of the most famous Robber Barons were John F. Rockefeller, owner of the Standard Oil Company, and Andre Carnegie, owner of the Steel Company.

The positive impact of these businessmen was that they invested millions of dollars in developing their industries and the creation of thousands of jobs.  

However, the challenges that the national economy faced because of their monopolistic practices were that the presence of their huge companies resulted in the lack of competition in their industries. They grew by buying other companies to the degree they became monopolies that dominated the industry. In these companies workers labored for long hours a day and received low salaries. They also worked under unhealthy conditions that put them at risk. That is why they started to demand better working conditions and began to form labor unions.

the answer is a. since they were a huge producer of cotton and wanted the most money for it.