Developmental tasks refer to the specific skills and abilities that individuals are expected to acquire at each stage of development. These tasks are influenced by social and cultural expectations and play a crucial role in shaping an individual's development.

Developmental hazards, on the other hand, are factors that can hinder or disrupt normal development. These hazards can include poverty, abuse, neglect, and other adverse conditions that impede a child's ability to meet their developmental tasks.

Conflicts, in the context of development, refer to the psychosocial conflicts that individuals face at different stages of their lives. These conflicts, as proposed by Erik Erikson, involve a tension between two opposing tendencies or desires. For example, the conflict in adolescence is identity vs. role confusion, where individuals are expected to form a coherent sense of self while also exploring different roles and identities.

Cognitive abilities, the correct answer, are the mental processes and capacities that individuals use to acquire knowledge, think, problem-solve, and understand the world around them. These abilities develop and change across the lifespan and are influenced by both biological maturation and environmental experiences.

Explanation:
- Developmental tasks: Developmental tasks are the specific skills and abilities that individuals are expected to acquire at each stage of development. These tasks are influenced by social and cultural expectations and are seen as important markers of healthy development. For example, in early childhood, developmental tasks may include acquiring language skills, developing self-control, and learning social skills.
- Developmental hazards: Developmental hazards are factors that can hinder or disrupt normal development. These hazards can include poverty, abuse, neglect, exposure to violence, and other adverse conditions that impede a child's ability to meet their developmental tasks. These hazards can have long-lasting negative effects on a child's physical, cognitive, and socio-emotional development.
- Conflicts: Psychosocial conflicts refer to the internal tensions or struggles that individuals face at different stages of their lives. These conflicts, as proposed by Erik Erikson in his psychosocial theory of development, involve a tension between two opposing tendencies or desires. For example, in adolescence, individuals experience the conflict of identity vs. role confusion, where they are expected to form a coherent sense of self while also exploring different roles and identities. Resolving these conflicts successfully contributes to healthy development and the formation of a strong sense of identity.
- Cognitive abilities: Cognitive abilities refer to the mental processes and capacities that individuals use to acquire knowledge, think, problem-solve, and understand the world around them. These abilities develop and change across the lifespan and are influenced by both biological maturation and environmental experiences. For example, in early childhood, cognitive abilities such as object permanence and symbolic thinking emerge, while in adolescence, individuals develop more advanced cognitive abilities such as abstract reasoning and hypothetical thinking.
Overall, while all of these factors play a role in development, cognitive abilities specifically highlight the social expectations for every stage of development as they represent the mental capacities individuals are expected to acquire during each phase of their lives.