Answer:
The correct answer would be A) genes and the environment.
The phenotype of an individual is mainly determined by two factors; its genetic make-up and environment.
The genes are the proteins coding sequences of the chromosomes. They lead to the production of particular proteins which help in the development of particular phenotypes.
For example, the blood group of a person is determined by the gene.
In addition, the environment helps in determining the levels of expressiveness of the genes that is, how much proteins would be synthesized.
For example, sports and nutrition complement the development of physical, social, and mental health.