Which factors significantly influence children's development and child care professionals' planning?

The correct choice highlights the importance of both internal and external factors in shaping children's development and influencing the planning by child care professionals. Internal factors include aspects such as a child’s individual characteristics, temperament, family dynamics, and genetic influences. These elements play a crucial role in how a child responds to their environment and experiences.

External factors encompass a broader range of influences, such as cultural, societal, and economic conditions. These factors can affect children's opportunities for learning and development, the quality of relationships they build, and the physical environment they grow up in. For example, access to quality education, healthcare, and community resources are external elements that can have a profound impact on a child’s growth.

By considering both internal and external factors, child care professionals can create more holistic and informed plans that cater to the diverse needs of children and their families. This approach ensures that they are equipped to support each child's unique development pathway effectively.