**Core Concept**
Delayed puberty in females refers to the absence of secondary sexual characteristics and no menstruation by the age of 13 years or 2 years after the onset of puberty in a peer group. This condition is often associated with underlying hormonal imbalances, particularly low levels of estrogen.

**Why the Correct Answer is Right**
The primary cause of delayed puberty in females is insufficient production of gonadotropin-releasing hormone (GnRH) from the hypothalamus, leading to reduced secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland. As a result, the ovaries do not produce sufficient estrogen, which is essential for the development of secondary sexual characteristics and the initiation of menstruation.

**Why Each Wrong Option is Incorrect**
**Option A:** **Hyperprolactinemia** is a condition characterized by elevated levels of prolactin, which can suppress GnRH secretion and lead to hypogonadism. However, it is not a common cause of delayed puberty in females.
**Option B:** **Polycystic Ovary Syndrome (PCOS)** is a hormonal disorder that affects ovulation and insulin sensitivity, but it typically presents with signs of hyperandrogenism and irregular menstrual cycles, not delayed puberty.
**Option C:** **Turner Syndrome** is a genetic disorder that affects females, characterized by the absence of one X chromosome. It is associated with short stature, ovarian dysgenesis, and primary amenorrhea, but it is not a common cause of delayed puberty.

**Clinical Pearl / High-Yield Fact**
It is essential to differentiate between primary and secondary amenorrhea in females. Primary amenorrhea refers to the absence of menstruation in a woman who has never menstruated, whereas secondary amenorrhea refers to the cessation of menstruation in a woman who has previously menstruated.

**Correct Answer:** D.