In 1998, paleoanthropologist Rick Potts, of the Smithsonian Institution, published an article in The Yearbook of Physical Anthropology, a peer-reviewed journal. The article was titled “Environmental Hypotheses of Hominin Evolution.” In his paper, Potts provided evidence to support his claim that great variations in environmental conditions over time were responsible for the adaptability of humans and the success of our species. Why might this not be the best article to reference?

The article is not reflecting current knowledge.

Explanation:

Rick Potts had explained some thing which has already been established and published several years back by various scientist, researchers, biologist, ecologists and geologist.

Re publishing something again will not bring laurel to Pott, instead his article would not be considered a suitable article for reference.

Also , if Pott would have published any thing that talks of a way ahead of those previous publication, even then his article could be referred.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

thinking it would be physical characteristics