**Core Concept**
"Castration anxiety" is a key psychological defense mechanism observed during the phallic stage of Freud's psychosexual development, where the child develops unconscious fears of punishment or loss of reproductive organs due to the Oedipus and Electra complexes.

**Why the Correct Answer is Right**
During the phallic stage (ages 3–6), children develop unconscious desires for the opposite-sex parent and fear of retaliation, especially from the same-sex parent. In boys, this manifests as **castration anxiety**—a fear that the father will castrate them to punish their desire. This anxiety arises from the child's realization of the father's power and the potential loss of masculinity. The phallic stage is marked by the development of genital identity and the conflict between libidinal urges and societal repression, making castration anxiety a central feature.

**Why Each Wrong Option is Incorrect**
Option A: Oral stage (0–1 year) involves mouth-related behaviors and gratification, not castration anxiety.
Option B: Anal stage (1–3 years) focuses on bowel control and toilet training, with issues related to autonomy and expulsion, not sexual fears.
Option D: Genital stage (adolescence onward) involves mature sexual identity and social integration, where such anxieties are resolved, not active.

**Clinical Pearl / High-Yield Fact**
Castration anxiety is a hallmark of the phallic stage and reflects the child’s unconscious conflict between desire and repression—this concept is foundational in understanding early psychodynamic theory and is often tested in psychiatry exams.

✓ Correct Answer: C. Phallic