**Core Concept**
Hypogonadotropic primary amenorrhoea is a condition characterized by low levels of **gonadotropin-releasing hormone (GnRH)**, leading to decreased production of **luteinizing hormone (LH)** and **follicle-stimulating hormone (FSH)**, resulting in ovarian dysfunction. This condition is often treated by replacing the deficient hormones. The underlying principle involves stimulating the ovaries to produce **estrogen** and induce menstruation.

**Why the Correct Answer is Right**
The correct treatment involves replacing the deficient hormones to stimulate the ovaries. **Pulsatile GnRH** or **FSH/LH** replacement is often used to treat hypogonadotropic hypogonadism. This approach aims to mimic the natural hormonal pulses, promoting **follicular growth** and **ovulation**.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not a standard treatment for hypogonadotropic primary amenorrhoea.
**Option B:** Incorrect as it is not directly related to treating the hormonal deficiency.
**Option C:** Incorrect because, although related to fertility, it is not the primary treatment for hypogonadotropic primary amenorrhoea.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that **GnRH** replacement should be pulsatile to mimic the natural hormone secretion pattern, as continuous administration can lead to **pituitary desensitization**.

**Correct Answer:** D. Pulsatile GnRH.