“Genes and environmental effects are often part of the explanation. “
“...disease-causing alleles of one gene may be suppressed by alleles of another gene elsewhere in the genome, or a person's overall health may influence the strength of a disease phenotype.”
https://www.khanacademy.org/science/high-school-biology/hs-classical-genetics/hs-non-mendelian-inheritance/a/polygenic-inheritance-and-environmental-effects
I believe it's D don't take my word for it.
C. pass those traits on to future generations
The right option is; to develop family pedigrees and inform clients of possible options.
Genetic counselors are trained specialists and part of the health care system that determine possible risk factors of hereditary disorders in patients. They function by analyzing patient histories (pedigree), providing genetic testing and diagnosis, performing genetic risk calculations, counseling and educating patients and their families about potential health risks and available options.
