Answer: D - Sigmund Freud is the psychologist who defined the structural model of the psyche: ego, superego, and id.
Key Takeaway: Sigmund Freud defined three theoretical constructs of the human psyche that influence the person’s mental life. The id is thought to govern basic drives such as sex and violence while the ego is more organized and grounded in the reality of the outside world. The superego, on the other hand, governs higher ideals of the human psyche and aims to act in a socially acceptable manner.