Lena is reading a story book with her 5-year-old son. Lena points to the illustrations, asks her son to sound out certain words, and acts out the dialog between characters. Lena's interactive mentoring exemplifies Vygotsky's notion of:

Scaffolding

Explanation:

Scaffolding  , according to the concept of Vygotsky is defined as teaching method that involves teacher or to demonstrates the act, interact with student to hint and make them understand concepts,etc so that student can perform the task and achieve goal.

According to the question, Lena is using scaffolding method for interacting and teaching her son so that he can produce certain sounds, they can involve in dialog reading etc.This will improve his understanding achieve learning goals.

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answer; criterion validity