**Core Concept**
Clomiphene citrate is a selective estrogen receptor modulator (SERM) used in the treatment of infertility in women with ovulatory dysfunction. It primarily works by competitively binding to estrogen receptors in the hypothalamus, which leads to an increase in gonadotropin-releasing hormone (GnRH) secretion and subsequently follicle-stimulating hormone (FSH) release.

**Why the Correct Answer is Right**
Clomiphene citrate binds to estrogen receptors in the hypothalamus, which is responsible for regulating the reproductive axis. By occupying these receptors, clomiphene citrate decreases the negative feedback of estrogen on GnRH secretion, resulting in an increase in GnRH release and subsequently FSH release from the anterior pituitary gland. This increase in FSH stimulates the growth and maturation of ovarian follicles, leading to ovulation.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because clomiphene citrate does not primarily work by directly stimulating the release of gonadotropins.
**Option B:** This option is incorrect because while clomiphene citrate does increase estrogen levels, it does so indirectly by stimulating follicular growth and maturation.
**Option C:** This option is incorrect because clomiphene citrate does not work by blocking the action of estrogen at the level of the endometrium.

**Clinical Pearl / High-Yield Fact**
Clomiphene citrate is often used as a first-line treatment for ovulatory dysfunction in women with polycystic ovary syndrome (PCOS). However, it should be used with caution in women with a history of endometriosis or uterine fibroids, as it may stimulate the growth of these conditions.

**Correct Answer: C. Clomiphene citrate works by competitively binding to estrogen receptors in the hypothalamus, leading to an increase in GnRH and FSH release.**