Which of the following forces causes comets to regularly return to the inner solar system after being gone for many years?

What is the evidence that depression can be linked to genetic as well as environmental factors? a. all individuals in similar stressful environments do not experience depression. b. all individuals with the gene variation tied to depression do not experience depression. c. individuals with a combination of environmental stress and gene variation are more likely to experience depression d. all of the above select the best answer from the choices provided оа 0 0 0