Which was least likely to have been a component of earth’s atmosphere before life began?

Read this passage: wendy is trying to learn more about the city's role in a chemical spill that occurred a few miles from her apartment. when she finds only a very short article in the local newspaper, she searches for articles on larger newspapers' websites to determine what might have been left out of the original article. which method of identifying bias is most clearly used in the passage? a. considering motivations for bias b. using a variety of media sources for information c. fact-checking stories d. comparing different stories on the same topic