Ovulation is associated with sudden rise in the level of which of the following hormone?

**Core Concept**
Ovulation is a critical phase in the menstrual cycle, marked by the release of a mature ovum from the ovarian follicle. This process is accompanied by a surge in specific hormone levels, which play a crucial role in preparing the body for potential fertilization.

**Why the Correct Answer is Right**
The sudden rise in the level of luteinizing hormone (LH) triggers ovulation. LH is produced by the anterior pituitary gland and binds to its receptor on the surface of granulosa cells in the ovarian follicle. This binding event activates the ovulation process, causing the follicle to rupture and release the ovum. The surge in LH is a critical event in the menstrual cycle, and its timing is precisely regulated by a complex interplay of hormonal and neural signals.

**Why Each Wrong Option is Incorrect**
**Option A:** Estrogen - Although estrogen levels do increase during the follicular phase of the menstrual cycle, the sudden rise in estrogen is not responsible for triggering ovulation. Instead, estrogen helps to stimulate the growth of the follicle and prepare the endometrium for potential implantation.
**Option B:** Progesterone - Progesterone levels increase after ovulation, helping to prepare the endometrium for implantation. However, it is not the hormone responsible for triggering ovulation.
**Option C:** FSH - Follicle-stimulating hormone (FSH) is another hormone produced by the anterior pituitary gland that plays a crucial role in follicular growth and development. However, FSH levels actually decrease during the late follicular phase, allowing LH to surge and trigger ovulation.

**Clinical Pearl / High-Yield Fact**
To remember the key hormones involved in ovulation, use the mnemonic "LH-ovulates, FSH-follicles": Luteinizing hormone (LH) triggers ovulation, while follicle-stimulating hormone (FSH) helps to stimulate follicular growth.

**Correct Answer: C. LH**