Correct Answer: A

Rationale: Physical activity is known to have a positive impact on mental health by reducing symptoms of anxiety and depression. Choice B is incorrect because physical activity generally improves both mood and alertness. Choice C is incorrect as physical activity tends to increase mood, alertness, and energy levels. Choice D is incorrect as physical activity actually increases neural activity in the cerebral cortex, which is associated with improved cognitive function and mental well-being.

Correct Answer: B

Rationale: Correct answer: School-age children master concrete operational tasks gradually, in a continuum of acquisition. Piaget's theory suggests that children develop cognitive abilities in stages, with concrete operational tasks being acquired gradually as part of this process. Choices A, C, and D are incorrect because concrete operational tasks are not typically mastered all at once, much later than Piaget believed, or necessarily after mastering abstract thinking.

Correct Answer: A

Rationale: Possible selves are ideas about what one might become in the future, which increase during the transition from early to middle adulthood. This period is characterized by individuals exploring and considering different potential future selves. Self-doubt (choice B) typically decreases as individuals become more confident and self-assured in middle adulthood. Destructiveness (choice C) is not a common developmental trend during this period. Autonomy (choice D) is a concept related to independence and self-governance, which may develop over a person's lifespan but does not specifically increase during the transition from early to middle adulthood.

Correct Answer: B

Rationale: John Bowlby believed that the infant-caregiver bond has lifelong consequences for human relationships. This is supported by his theory of attachment, where he emphasized the importance of early attachment experiences in shaping individuals' future relationships. Choice A is incorrect as it does not reflect Bowlby's main focus on attachment theory. Choice C is incorrect as Bowlby's theory suggests that attachment is more than just instinctual. Choice D is also incorrect as Bowlby's work actually paved the way for the study of attachment patterns in humans.

Correct Answer: C

Rationale: In middle childhood, self-esteem becomes more differentiated and organized into a hierarchy based on various domains of competence. This period marks a time when children start to compare their abilities in different areas, such as academic performance, social skills, and physical abilities. Toddlerhood and preschool years are characterized by the development of basic self-awareness and self-concept, but self-esteem hierarchy typically emerges later in middle childhood and further solidifies in adolescence as individuals navigate complex social dynamics and personal identities.