Which of the Following Is the Best Example of the Concept

Multiple Choice

Which of the following is the best example of the concept of a zone of proximal development?

A) Sherri works on her algebra homework for two hours without being able to answer a single question correctly.
B) Jeff makes a note of the homework assignment for his last period class and completes it while riding home on the school bus.
C) Cindy explains to her younger sister how to solve a problem in math by organizing the information in a new way.Her younger sister can then complete her homework.
D) A mother shows her 8-month-old infant flashcards of words in different languages while she repeats each word on the card.