**Core Concept**
The rate of cerebrospinal fluid (CSF) production is a critical aspect of its dynamics, which helps maintain the delicate balance of pressure within the cranial vault. The choroid plexus, located in the ventricles of the brain, is the site of CSF production. The rate of CSF formation is essential for understanding various neurological conditions, such as hydrocephalus.

**Why the Correct Answer is Right**
The correct answer, **5000 c.c.**, is based on the rate of CSF production by the choroid plexus, which is approximately 5000 mL (or 5 L) per day. This is achieved through the active transport of ions and water across the choroid plexus epithelium, resulting in the formation of CSF with a unique composition. The composition of CSF is distinct from plasma, with lower levels of certain ions and proteins.

**Why Each Wrong Option is Incorrect**
* **Option A:** 1000 c.c. is too low, as it would not be sufficient to maintain the normal pressure within the cranial vault.
* **Option B:** 2000 c.c. is still lower than the actual rate of CSF production, and it would lead to inadequate CSF volume and potential complications.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the rate of CSF production is closely related to the rate of CSF absorption, which occurs through the arachnoid granulations. An imbalance between production and absorption can lead to various neurological conditions, such as hydrocephalus or normal-pressure hydrocephalus.

**✓ Correct Answer: C. 5000 c.c.**