Answer:
mouth
Step-by-step explanation:
Sigmund Freud has given the psychoanalytic theory in which he has mentioned five distinct stages.
Oral stage: This is the very first stage of Freud's theory which starts at the birth of a child and lasts through eighteen months of age. At this stage, an infant's primary focus is on the mouth and involves activities such as taking things in mouth, eating, and therefore an infant grasp or gains pleasure via mouth.