**Core Concept**
Diplopia is a symptom characterized by the perception of two or more images of a single object, resulting from an imbalance in the coordination of the extraocular muscles or a problem with the nerves that control these muscles. It is a common presenting feature of various neurological and ophthalmological conditions.

**Why the Correct Answer is Right**
Diplopia typically arises from a problem with the lateral rectus muscle, which is innervated by the abducens nerve (cranial nerve VI). Conditions affecting this muscle or nerve, such as thyroid ophthalmopathy, orbital fractures, or cranial nerve VI palsy, often cause diplopia. However, some conditions do not typically present with diplopia as a primary symptom.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because diplopia can be a presenting feature of conditions affecting the medial rectus muscle, such as thyroid ophthalmopathy or orbital fractures.
* **Option B:** This option is incorrect because diplopia can be a presenting feature of conditions affecting the trochlear nerve (cranial nerve IV), such as trochlear nerve palsy.
* **Option C:** This option is incorrect because diplopia can be a presenting feature of conditions affecting the oculomotor nerve (cranial nerve III), such as oculomotor nerve palsy.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that diplopia can be a "red flag" symptom, indicating a potentially serious underlying condition that requires prompt evaluation and treatment. A thorough history and physical examination, including assessment of eye movements and pupillary responses, are crucial in diagnosing the underlying cause of diplopia.

**Correct Answer:** C.