This is a very easy paragraph analysis question. The answer is c. "Over time, scientific knowledge is reevaluated and extended through new scientific research." The reason why the answer is C., is because the chronological order of the study of genetics is as follows:
- Mendel does his pea plants experiments, but did not know how traits were passed to the offspring.
- Avery concludes that DNA is the "material" that passes on traits to the offspring, probably using Mendel's research and his own research (pneuonimia virus research) as well.
- Since the existence of DNA was published, Watson and Crick used it to identify an accurate model of the structure of DNA, using the four bases: cytosine, adenine, guanine, and thymine.
Overall, we see a trend of scientists publishing results based on what scientists did before.