Question

How did John D. Rockefeller horizontally integrate his monopoly in 1882?
He created a trust that controlled ninety percent of the nation's oil refineries.
He created a trust that controlled oil wells, refineries, and distribution networks.
He purchased coal plants around the country to add to his business.
He purchased iron mines around the country to add to his business.

Answer 1

He created a trust that controlled ninety percent of the nation's oil refineries.

Explanation: horizontal integration means bringing together firms at the same stage (refining). The 1882 Standard Oil Trust pooled many refineries to dominate the refining market.