Test Lev Vygotsky's sociocultural theory

1st QUESTION: What is the fundamental premise of Lev Vygotsky's sociocultural theory?

That development is a solitary and individual process
That development occurs in fixed and universal stages
That the support of adults and peers allows the development of higher psychological functions
That language is a sign of immaturity in children

As a tool for thinking out loud, guiding your own behavior and thinking
Only to communicate with other people
As a clear sign of immaturity that must be corrected
To demonstrate that they have already reached the level of potential development

What the child is able to do completely independently
The skills that the child has already fully internalized
What the child can achieve when collaborating with more capable peers or under the guidance of an adult
Using egocentric speech to solve problems