Which One of the Following Statements Most Accurately Describes Lev

Which one of the following statements most accurately describes Lev Vygotsky's theory of cognitive development?

A) Children's cognitive growth should be judged on the basis of their actual developmental level, not on the basis of their level of potential development.
B) Cognitive development progresses through four distinct stages; each stage is characterized by increasingly more complex thought and language.
C) Children develop by working on challenging tasks with the assistance of more competent individuals.
D) Language and thought, although closely intertwined in the first few years of life, become increasingly distinct entities over time.