Correct Answer: C

Rationale: The correct answer is C: Phallic. Freud's psychosexual stage that occurs between ages 3 and 5 and includes the Oedipal period is the phallic stage. This stage is characterized by the Oedipus complex for boys and the Electra complex for girls. Choices A, B, and D are incorrect because the oral stage typically occurs during the first year of life, the anal stage occurs around ages 2 to 3, and the genital stage is the final stage in Freud's theory of psychosexual development.

Correct Answer: B

Rationale: The correct answer is B. Extinction is the process of eliminating a conditioned response by repeatedly presenting the conditioned stimulus without the unconditioned stimulus. This helps in reducing or eliminating undesired behaviors. Choice A is incorrect because extinction does not strengthen the conditioned response but weakens it. Choice C is also incorrect as extinction is a valid technique used in treating disorders by reducing unwanted behaviors. Choice D is incorrect as extinction does not involve intensifying the conditioned response but rather diminishing it.

Correct Answer: B

Rationale: The correct answer is B. Socioeconomic factors like income and education levels are key determinants of mental health. They influence access to resources such as healthcare, housing, and social support systems, which can impact an individual's mental well-being. Additionally, socioeconomic factors can contribute to stress levels and overall quality of life, which in turn affect mental health. Choice A is incorrect because socioeconomic factors do play a significant role in mental health outcomes. Choice C is incorrect as socioeconomic factors have a broad impact on mental health beyond extreme cases. Choice D is also incorrect as numerous studies have shown the clear impact of socioeconomic factors on mental health.

Correct Answer: D

Rationale: Studying identical twins raised in different environments allows researchers to understand the impact of genetics versus environmental factors on traits. Choice A is incorrect because differences in brain function can be influenced by a variety of factors and not solely by environmental differences. Choice B is incorrect as concordance rates tend to be higher in identical twins reared together due to shared genetics and environment. Choice C is incorrect because genetics do not change due to being raised in different environments.

Correct Answer: D

Rationale: Down syndrome is caused by possessing an extra chromosome in chromosome 21, not by a chemical imbalance (choice A), a gene on the X chromosome (choice B), or possessing an extra X chromosome (choice C). The presence of an additional chromosome 21 disrupts the normal course of development and leads to the characteristics associated with Down syndrome.