Final answer:
A. Epigenetic links between gene expression and environmental factors support the medical perspective on psychological disorders.
Step-by-step explanation:
The answer is a. Epigenetic links between gene expression and environmental factors and psychological disorders have provided support for the medical perspective on psychological disorders. Epigenetics refers to the changes in gene expression that occur during a single human lifetime. Environmental factors and mutations can contribute to these changes, leading to the development of psychological disorders. For example, studies have shown that exposure to smoking in childhood can impact adult height, and trauma can increase the likelihood of developing maladaptive symptoms. These findings suggest that both genetic and environmental factors play a role in psychological disorders.