Which of these must have happened first? A.Another scientific group researched a similar idea to the one Dow Chemical and the Nature Conservancy proposed and decided that it would not pay off. B.The EPA required companies to rid the air of industrial pollutants, such as nitrogen oxide, emitted by factories. C.Research determined that a 1,000-acre (405-hectare) forest would remove 4 to 7 short tons (3.6 to 6.4 metric tons) of nitrogen oxide annually.
In order for the idea proposed by Dow Chemical and the Nature Conservancy to be researched by another scientific group and determined to not pay off, both option A and option C must have happened first. The research determining the amount of nitrogen oxide removed by a forest is a prerequisite for the scientific group to assess the potential payoff of the proposed idea.
