A9-month-old infant who appears well nourished, alert, and happy is brought to the well-baby clinic for a routine physical examination. using freud's psychosocial theory of development, the nurse determines that the infant is in which stage.

A 9-month old baby would belong to oral stage. In this stage children’s pleasure center would be their mouths. It is the stage where we see them mostly indulged on activities centered on their mouths like sucking, cooing, biting, and even crying.