Correct Answer: C

Rationale: The correct answer is C: 'Interaction between genetics and environment.' The genetic study of identical twins reared apart helps in understanding how both genetics and environment play a role in shaping an individual's traits and behaviors. This type of study allows researchers to tease apart the effects of genetic inheritance from those of environmental influences. Choices A, B, and D are incorrect because the study of identical twins reared apart specifically focuses on the interplay between genetics and environment, rather than solely on differences in brain function, genetic influence on behavior, or the role of environmental factors alone.

Correct Answer: C

Rationale: Genes are made of DNA, which is the genetic material that carries the instructions for the development, functioning, growth, and reproduction of organisms. While chromosomes contain genes, they are not what genes themselves are made of. Proteins are involved in gene expression and regulation, but they are not the primary material genes consist of. Trisomes is an incorrect term in this context and does not relate to the composition of genes.

Correct Answer: B

Rationale: Object-relations theory is a psychodynamic theory that focuses on how individuals interact with others and their internalized relationships. Choice A is incorrect because object-relations theory goes beyond observable behaviors to explore internalized relationships. Choice C is incorrect because object-relations theory does not primarily emphasize cognitive processes. Choice D is incorrect because object-relations theory is not a cognitive-behavioral theory focused on changing thought patterns.

Correct Answer: D

Rationale: Biological discoveries have indeed led to a recognition of the role that genetic factors and other biological influences play in the development of many disorders. This understanding has shifted the focus from purely environmental explanations to acknowledging the significant impact of genetics and biology on mental health. Choices A, B, and C are incorrect because biological discoveries have not specifically addressed the subjectivity of definitions of abnormality, minimized the role of the environment in psychopathology, or definitively classified mental disorders as diseases that should only be handled by the medical profession.

Correct Answer: B

Rationale: Hormones play a critical role in regulating mood, behavior, and mental health, influencing everything from stress response to emotional stability. Choice A is incorrect because hormones have a significant impact on mental health in addition to physical processes. Choice C is incorrect as hormones do have a notable effect on behavior. Choice D is incorrect as hormones have broad functions beyond just reproductive processes.