**Core Concept**
The cavernous sinus is a critical venous structure located in the posterior aspect of the sphenoid bone, playing a key role in the drainage of blood from the brain. It is a dural venous sinus that forms part of the venous system of the brain.

**Why the Correct Answer is Right**
The cavernous sinus contains the internal carotid artery, the abducens nerve (CN VI), and the sympathetic plexus. The internal carotid artery passes through the superior wall of the cavernous sinus, while the abducens nerve, which is responsible for lateral rectus muscle innervation, traverses the lateral wall. Additionally, the cavernous sinus is also the site where the sympathetic nerves from the superior cervical ganglion synapse.

**Why Each Wrong Option is Incorrect**
**Option A:** The superior and inferior petrosal sinuses are venous structures located within the dura mater, but they are not contained within the cavernous sinus itself.
**Option B:** The inferior cerebral veins are small venous structures that drain blood from the surface of the brain, but they are not specifically contained within the cavernous sinus.
**Option C:** The sigmoid sinus is another dural venous sinus, but it is located in the posterior cranial fossa and is not contained within the cavernous sinus.

**Clinical Pearl / High-Yield Fact**
The cavernous sinus thrombosis is a serious condition that can lead to the spread of infection from the face to the brain, highlighting the importance of recognizing the anatomy and contents of the cavernous sinus.

**Correct Answer: C. The internal carotid artery, the abducens nerve (CN VI), and the sympathetic plexus.**