Did my subject John D Rockefeller create a positive or negative impact on America

John D Rockefeller was a positive impact on America. In 1870, He established his company called Standard Oil. By the 1880’s, his company controlled 90% of all oil pipelines in the U.S. Oil was a life changing impact on America, fueling people’s homes and allowing for materials to be made.

The answer is c because i know the answer is c