Okay, let's tackle this question about the third cranial nerve. The question is asking which of the options is NOT a characteristic of the oculomotor nerve (third nerve). First, I need to recall the main functions and anatomical features of the third nerve.

The oculomotor nerve is responsible for most of the eye's movements, specifically the superior, inferior, and medial rectus muscles, as well as the inferior oblique. It also innervates the levator palpebrae superioris, which raises the eyelid. Additionally, the third nerve carries parasympathetic fibers that control the pupillary constrictor muscles via the ciliary ganglion. The nerve exits the brainstem from the midbrain, specifically the tegmentum, and passes through the cavernous sinus before entering the orbit via the superior orbital fissure.

Now, the question is about an exception. Common characteristics of the third nerve include its role in eye movement, eyelid elevation, and the parasympathetic pathway for the pupil. The options that are incorrect would be those that don't align with these functions. For example, if an option states that the third nerve innervates the lateral rectus, that's incorrect because the lateral rectus is innervated by the sixth nerve (abducens). Another possible wrong option might be that it's a sensory nerve, which it isn't—it's purely motor and parasympathetic. Also, if an option mentions that the third nerve passes through the foramen rotundum, that's wrong because it goes through the superior orbital fissure.

The clinical pearl here is to remember that third nerve palsy typically causes ptosis, pupil dilation (due to loss of parasympathetic input), and impaired eye movements except for abduction (since the lateral rectus is controlled by the sixth nerve). So, the key points to remember are the muscles it innervates, its parasympathetic function, and its pathway.

**Core Concept**
The oculomotor nerve (CN III) innervates most extraocular muscles, the levator palpebrae superioris, and the pupillary constrictor via parasympathetic fibers. It originates in the midbrain tegmentum, exits the brainstem ventrally, and passes through the cavernous sinus and superior orbital fissure.

**Why the Correct Answer is Right**
The **abducens nerve (CN VI)**, not the oculomotor nerve, innervates the **lateral rectus muscle**, which abducts the eye. The oculomotor nerve controls the medial, superior, and inferior recti (adduction, elevation, depression) and the inferior oblique (elevation in adduction). A CN III palsy classically causes ptosis, pupil dilation (due to loss of parasympathetic input), and impaired eye movements except abduction.

**Why Each Wrong Option is Incorrect**
**Option A:** *“Innervates the levator palpebrae superioris”* is correct for CN III.
**Option B:** *“Contains parasympathetic fibers to the pupil”* is correct for CN III.
**Option C:** *“Exits the brainstem from the midbrain tegmentum”* is correct for CN III.

**Clinical Pearl / High

✓ Correct Answer: C. Enters orbit through the inferior orbital fissure