Answer: The sensual aspect of intercourse became more important.
Explanation:
There are different development stages in humans; from infant to adolescent to adulthood. The word "When humans begins to walk upright' shows the development stage of maturity. This usually takes place in adolescents. The sensual aspect of intercourse became more important. Sex is one of the drives that is behind every thought, feeling, and behavior.
Much like the human body and all its organs that make up organ systems that work together to help keep the person alive, cells have organelles that all work together to help keep the cell alive and make sure the cell carries out its purpose.
Myofibrillar proteins in the muscles would become most affected by limited nitrogen.
If it's wrong.. I'm sorry.
The answer is b. The increase in population suggests that a beneficial trait helped the species.
