What sort of monopoly did john rockefeller mostly have?

in 1870, he established standard oil, which by the early 1880s controlled some 90 percent of u.s. refineries and pipelines. critics accused rockefeller of engaging in unethical practices, such as predatory pricing and colluding with railroads to eliminate his competitors, in order to gain a monopoly in the industry. if this , a brainliest would be appreciated!

explanation:

the answer is c     : )

explanation:

i don't have an explanation because i don't know, but i think the answer is c because i googled it and google is right : ) just kidding google isn't allways right but the answer is still c. i hope this !

explanation:

ur mom was made