**Core Concept**
The underlying principle being tested is the hormonal regulation of the menstrual cycle, specifically the role of estrogen and progesterone in ovulation. Anovulatory cycles occur when there is a disruption in the normal feedback mechanisms between the hypothalamus, pituitary gland, and ovaries, leading to inadequate estrogen and progesterone production.

**Why the Correct Answer is Right**
In anovulatory cycles, the lack of progesterone production prevents the endometrium from preparing for a potential pregnancy. As a result, the endometrium does not thicken, and there is no shedding of the endometrium during menstruation. This is often accompanied by irregular menstrual bleeding patterns, including prolonged or heavy bleeding. The correct answer reflects this hormonal imbalance and its effects on the menstrual cycle.

**Why Each Wrong Option is Incorrect**
* **Option A:** While estrogen levels may be elevated in some cases of anovulatory cycles, this is not a defining characteristic. Estrogen levels can fluctuate during anovulatory cycles, but this option does not accurately capture the underlying hormonal imbalance.
* **Option B:** This option is incorrect because anovulatory cycles are not typically associated with increased androgen levels. In fact, anovulatory cycles are often characterized by low levels of androgens.
* **Option C:** This option is incorrect because anovulatory cycles are not typically associated with increased levels of follicle-stimulating hormone (FSH). In fact, FSH levels may be low or normal in anovulatory cycles.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that anovulatory cycles can be caused by a variety of factors, including polycystic ovary syndrome (PCOS), hypothalamic amenorrhea, and premature ovarian failure. Identifying the underlying cause of anovulatory cycles is crucial for developing an effective treatment plan.

**Correct Answer: C. Lack of progesterone production leading to inadequate endometrial preparation.**