**Core Concept**
Precocious puberty refers to the premature onset of puberty, before the age of 8 in girls and 9 in boys. CNS tumors can cause central precocious puberty by releasing gonadotropin-releasing hormone (GnRH), leading to an increase in luteinizing hormone (LH) and follicle-stimulating hormone (FSH) production, which stimulates the gonads to produce sex hormones.

**Why the Correct Answer is Right**
The most common CNS tumor to cause precocious puberty is a **craniopharyngioma**. This type of tumor arises from the pituitary gland or its stalk and can cause an overproduction of GnRH, leading to precocious puberty. The tumor may also compress the pituitary gland, causing an increase in LH and FSH secretion. The resulting surge in sex hormones can cause premature development of secondary sexual characteristics.

**Why Each Wrong Option is Incorrect**
* **Option A:** Germinomas are rare CNS tumors that can cause precocious puberty, but they are less common than craniopharyngiomas.
* **Option B:** Optic gliomas are CNS tumors that can cause vision problems and other symptoms, but they are not typically associated with precocious puberty.
* **Option D:** Meningiomas are benign brain tumors that can cause a variety of symptoms, but they are not commonly associated with precocious puberty.

**Clinical Pearl / High-Yield Fact**
Craniopharyngiomas are typically suprasellar tumors that can cause visual disturbances, diabetes insipidus, and other symptoms due to their proximity to the optic chiasm and pituitary gland.

**Correct Answer: C. Craniopharyngioma**