Answer:
D. that following rules of exogamy is adaptively advantageous.
Explanation:
Incest means sexual relationship between the members sharing blood relations. The incest taboo is applied to a varying degree among different cultures according to the degree of blood connection among the members like in some cultures it is applied to immediate siblings, others attach it to third level relatives. However, the most acceptable explanation of the incest taboo is the inbreeding because children of close genetic chain parents tend to have genetic disorders.