Which of the following is NOT one of Freud's stages of psychosexual development?

Freud's stages of psychosexual development include the oral, anal, phallic, latency, and genital stages. The latency stage occurs after the phallic stage and is characterized by a period of relative calm in terms of sexual feelings. The anal stage, which comes after the oral stage, focuses on toilet training and the child’s control over bodily functions. The genital stage represents the maturation of sexual interests and the awakening of sexual feelings during puberty.

In contrast, the preoperational stage is a concept developed by Jean Piaget, not Sigmund Freud. Piaget's stages of cognitive development include the sensorimotor, preoperational, concrete operational, and formal operational stages, which address how children's thinking develops over time rather than focusing on psychosexual development. Therefore, identifying the preoperational stage as not fitting within Freud's framework is accurate.