Chemical X was used widely in the United States as an insecticide for many years. Eventually, research showed chemical X was a persistent chemical that bioaccumulated and biomagnified in the environment. The chemical was later banned from use in the United States. You are writing a report on the history of chemical X in the United States. Your instructor says that all sources used for your report must be primary sources. Which source would you choose? a. an interview with the scientist who created chemical X.
b. a textbook from an environmental toxicity class.
c. a news website story about chemical X
d. an original research article in a scientific journal about the effects of chemical X.