In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

Question: A child must be taught to be more autonomous and learn to eat without help. If he first learns to hold a spoon, then to grab some puree and is finally able to take it to his mouth, and the parents congratulate him, it means that they have used positive reinforcement and the technique of successive approximations. This technique is also called:
Options: <0> Learning by observation. <1> Molding <2> Vicarial learning. <3> Reward. <4> Training with emission.
nursery