In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Q: Question: What is the name of the distance between what a child is capable of doing for himself and what he is capable of doing if an adult, or another more capable child, helps him ?:
Options: <1> Scaffolding. <2> Self-regulation. <3> Tertiary circular reaction. <4> Near (or proximal) development zone. <5> Shared attention area.
A:
4