## **Core Concept**
The core concept being tested here is the marker of ovarian reserve, which is crucial in assessing infertility. Ovarian reserve refers to the quantity and quality of eggs remaining in the ovaries. A marker of ovarian reserve helps in evaluating a woman's potential response to ovarian stimulation.

## **Why the Correct Answer is Right**
The correct answer, **Anti-Müllerian Hormone (AMH)**, is a widely accepted marker of ovarian reserve. AMH is produced by the granulosa cells of small antral follicles in the ovaries and reflects the number of remaining follicles. It is a reliable indicator of ovarian reserve because its levels are directly correlated with the number of antral follicles. AMH levels are used to predict ovarian response to stimulation, helping in the management of infertility.

## **Why Each Wrong Option is Incorrect**
- **Option A: FSH (Follicle-Stimulating Hormone)** - While FSH is used to assess ovarian reserve, it is not as specific or reliable as AMH. FSH levels can fluctuate and do not directly reflect the number of follicles.
- **Option B: LH (Luteinizing Hormone)** - LH is crucial for ovulation but is not a marker of ovarian reserve. It does not directly reflect the number of remaining eggs.
- **Option D: Inhibin B** - Inhibin B is another hormone produced by the ovaries and does reflect ovarian function. However, it is less specific and less commonly used than AMH for assessing ovarian reserve.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **AMH levels are independent of menstrual cycle day** and can be measured at any time during the menstrual cycle, making it a convenient marker for ovarian reserve. Low AMH levels indicate reduced ovarian reserve, suggesting a poorer response to ovarian stimulation.

## **Correct Answer:** . Anti-Müllerian Hormone (AMH)