The correct answer is sensorimotor
Piaget called the stage from birth to 2 years of the child's life as a sensorimotor period or sensorimotor stage.
The human being has a unique cognitive capacity in the world. It is what distinguishes us from other animals, which makes us understand this distinction, which endows us with the ability to communicate, which gives us subsidies to (try) to understand the world.
It is known that the first years of life are fundamental in the development of human beings. This conception started scientifically only in the beginning of the 20th century, with the studies of the child and the infantile behavior. Since then, a series of researches has been established on different aspects of the child's psychic life, his development and the conception of intelligence (and the formation of that intelligence) in the child.
An important development theorist, Jean Piaget, was very concerned with the question of how human beings develop their knowledge about reality, how thought processes happen. His studies have brought about a huge advance in what is now called developmental psychology.
 
        
             
        
        
        
<span>This is thanks to the foot-in-the-door phenomenon. This phenomenon works by first getting someone to agree or comply with something that is a small and not too tedious task (here, this would be the agreement to stay on the phone and listen to the pitch). Next, once the small task is completed, the person is more likely to agree to a much larger task (here, whatever the telemarketer is selling).</span>
        
             
        
        
        
Answer:
Peer group
Explanation:
Peer group - 
It refers to the combination of people , combined together because of some common interest , is referred to as a peer group. 
This group tries to attract and influences other person to join and follow their group . 
A peer group can be good as well as bad in belief . 
Hence , from the given scenario of the question , 
The correct answer is peer group .