Answer:
The answer is the Id.
Step-by-step explanation:
Freud believed human personality was divided into three fundamental structures: the Id, the Ego and the Supergo. The Id is the only structure that is present from birth, and is driven by instinct and the pleasure principle. In infants, for example, the Id is responsible for the sense of thrist and hunger.
Some of the impulses driven by the Id may be unrealistic or socially unacceptable. For this reason, the Ego structure must regulate these desires and turn them into more admissible alternatives.