Which of the following best describes the most valuable aspect of Vygotsky's contribution to research on child development?
A. He explained how children learn language through an innate mechanism
B. He explained how children process and synthesize individual bits of of information
C. He provided a precise definition for each concept he proposed, making it easy to test them experimentally
D. He explained the importance of social interaction in promoting cognitive development

D. He explained the importance of social interaction in promoting cognitive development.

Explanation:

A seminal Russian psychologist known as Lev Vygotsky expressed the sociocultural theory. On the basis of his experience, he strongly believe that social interaction is the main key and play's critical role in the development of children's learning because children will be in process of continuous learning by social interaction.  

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.

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