Correct Answer: D

Rationale: The correct answer is D. Development is best understood as a series of complex exchanges between nature (genetic factors) and nurture (environmental influences). This perspective emphasizes the interaction and interplay between genetic predispositions and environmental experiences in shaping an individual's development. Choices A and B are too extreme as they suggest that development is solely determined by genetics or solely influenced by the environment, which is not the case. Choice C is incorrect as development is not viewed as an unsolvable puzzle but rather as a dynamic process influenced by multiple factors.

Correct Answer: D

Rationale: The correct answer is D: 'can lead to cognitive deterioration.' Depression, particularly in older adults, can significantly impair cognitive function, leading to further mental health challenges. Choices A, B, and C are incorrect. Depression does not necessarily decline with age, treatment coverage may vary, and depression can indeed be related to physical illness or pain.

Correct Answer: C

Rationale: Passionate love is characterized by intense emotions and physical attraction, which are common in the early stages of relationships. Compassionate love involves deep affection, but it develops over time based on mutual respect, trust, and intimacy. Affectionate love is warm and tender, but it may not necessarily have the intense emotions associated with passionate love. Companionate love is based on friendship, respect, and affection, but it may lack the intense emotions and physical attraction that characterize passionate love.

Correct Answer: C

Rationale: Free radicals may contribute to oxidative stress, increasing the risk of conditions associated with a high-fat diet. When consuming a high-fat diet, the body may produce more free radicals, leading to oxidative damage. Sex hormones, over-the-counter medications, and low body weight do not directly heighten the effects of a high-fat diet like free radicals do.

Correct Answer: D

Rationale: The correct answer is 'social referencing.' Social referencing is a behavior where infants seek emotional information from a trusted person, usually a caregiver, to determine how to respond in uncertain situations. This process helps infants regulate their emotions and behaviors based on the cues they receive from the trusted individual. Choices A, B, and C are incorrect because self-control, give-and-take, and emotional self-regulation do not specifically involve seeking emotional information from others in uncertain situations, as social referencing does.