**Core Concept**
The Oedipus complex is a psychological concept that describes an unconscious, incestuous desire between a child and the opposite-sex parent. It is a central idea in psychoanalytic theory, first introduced by Sigmund Freud. This phenomenon is thought to be a normal part of child development, particularly during the phallic stage.

**Why the Correct Answer is Right**
The Oedipus complex arises due to the child's desire to possess the opposite-sex parent and eliminate the same-sex parent, leading to feelings of guilt and anxiety. This complex is thought to be a result of the child's desire for the opposite-sex parent's affection and attention, which is often accompanied by a sense of rivalry with the same-sex parent. The Oedipus complex is a crucial concept in understanding human development, particularly in the context of psychoanalytic theory.

**Why Each Wrong Option is Incorrect**
**Option B:** The Electra complex, on the other hand, is a similar phenomenon that occurs in girls, where they exhibit a desire for the father and a sense of rivalry with the mother. While it is related to the Oedipus complex, it is not the same concept.
**Option C:** Family incest refers to any form of sexual relationship between family members, which is not a specific psychological concept like the Oedipus complex.
**Option D:** The statement "None" is incorrect because the Oedipus complex is indeed a recognized psychological concept.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the Oedipus complex is a normal part of child development, and it does not necessarily indicate a pathological condition. However, if the complex persists into adulthood or is accompanied by other signs of psychological distress, it may warrant further evaluation and treatment.

**✓ Correct Answer: A. Oedipus complex**