Which of these statements is true about the introduction to a research paper?

a. it defines essential terms and concepts.
b. it intergrates material from various sources
c. it evaluates the argument of the paper

Which statement describes how favorable traits in a population relate to natural selection? they are the only traits that ever exist in the population. they build in the population over time. they are rarely passed on to offspring. they are found only in a few individuals within the population.