**Core Concept**
A cerebellopontine angle (CPA) tumor is a type of neoplasm that arises in the CPA, a region between the cerebellum and pons in the brainstem. This area is critical for balance, coordination, and hearing.

**Why the Correct Answer is Right**
The most common type of CPA tumor is the acoustic neuroma, also known as a vestibular schwannoma. These tumors arise from the Schwann cells that cover the vestibular nerve, which is responsible for balance and equilibrium. The growth of acoustic neuromas can compress the surrounding structures, including the facial nerve, trigeminal nerve, and the brainstem, leading to a range of neurological symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** Meningiomas are tumors that arise from the meninges, the protective membranes surrounding the brain and spinal cord. While they can occur in the CPA, they are not the most common type of tumor in this region.
**Option B:** Gliomas are a type of primary brain tumor that arise from glial cells. They can occur in various parts of the brain, including the CPA, but are less common than acoustic neuromas.
**Option C:** Chordomas are rare tumors that arise from the notochord, a structure that forms during embryonic development. While they can occur in the cranial base, they are not typically associated with the CPA.

**Clinical Pearl / High-Yield Fact**
Acoustic neuromas are often asymptomatic until they reach a significant size, at which point they can cause symptoms such as hearing loss, tinnitus, and balance problems.

**Correct Answer: C. Acoustic neuroma**