**Core Concept**
A carotico-cavernous fistula is an abnormal connection between the carotid arterial system and the cavernous sinus, leading to various ocular and neurological symptoms. This condition is often characterized by **vascular** and **neurological** manifestations. The **cavernous sinus** plays a crucial role in the pathophysiology of this condition.

**Why the Correct Answer is Right**
The correct answer is not provided, however, typical features of carotico-cavernous fistula include **exophthalmos**, **chemosis**, and **bruit**. The exact answer choice would depend on the options given, but generally, features not associated with carotico-cavernous fistula would be those unrelated to **increased venous pressure** or **arterialization of venous blood**.

**Why Each Wrong Option is Incorrect**
**Option A:** Would be incorrect if it described a common symptom, such as **visual disturbances**.
**Option B:** Might be wrong if it mentioned **pulsatile exophthalmos**, a classic sign.
**Option C:** Could be incorrect if it referred to **ocular bruit**, a sound heard over the eye.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that carotico-cavernous fistulas can lead to **increased intraocular pressure** and **vision loss** if left untreated. Early diagnosis and intervention are crucial.

**Correct Answer:** Not provided in the query.