How and when did the cold war come to and end? i will mark brainliest answer to the best explaniation and answer ~! king! ~ for your

In ohio in 1872, the cleveland massacre was a)a violent labor dispute at standard oil refineries in cleveland. b)a takeover by standard oil of the refineries in cleveland. c)an attempt to stop standard oil from becoming a monopoly. d)a failed attempt by standard oil to take over other refineries.