**Core Concept**
Hydrocephalus refers to the abnormal accumulation of cerebrospinal fluid (CSF) within the brain, leading to increased intracranial pressure and potentially causing damage to the brain tissue. This condition can result from various causes, including impaired CSF reabsorption, obstruction of CSF pathways, or overproduction of CSF.

**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of hydrocephalus, specifically the role of CSF circulation and reabsorption. In normal physiology, CSF is produced in the choroid plexus of the ventricles and circulates through the ventricular system, subarachnoid space, and arachnoid granulations, where it is reabsorbed into the venous system. In hydrocephalus, this process is disrupted, leading to accumulation of CSF and increased intracranial pressure.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately describe the pathophysiology of hydrocephalus. While CSF production is indeed increased in some cases, this is not the primary cause of hydrocephalus.
* **Option B:** This option is incorrect because it is not a true statement about hydrocephalus. CSF circulation is not directly affected by the condition.
* **Option D:** This option is incorrect because it is not a characteristic of hydrocephalus. The condition is typically associated with increased intracranial pressure, not decreased.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that hydrocephalus can present with a wide range of symptoms, from subtle cognitive impairments to severe neurological deficits, depending on the severity and duration of the condition. Early diagnosis and treatment are critical to preventing long-term damage to the brain.

**Correct Answer: C.**