(a). consider a population where selection favors one allele (b) over another allele
(b). which component would be least likely to counter the expected decrease of the b allele in the population?

Nonrandom mating

Explanation:

Nonrandom mating, also called Assortative mating, happens whenever the likelihood of matting two individuals in a population is not the same for all possible individual pairs.

Whenever the likelihood will be the same then people are as likely to match distant relatives as close relatives— this is random matching.

answer; ///i believe the correct answer is (b) the writing of the ancients who lived in india after the indus valley inhabitants died out;

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.