Okay, let's tackle this question about the sensory supply of the external auditory meatus. First, I need to recall the anatomy of the ear. The external auditory meatus is the ear canal leading to the eardrum. Sensory innervation usually comes from specific nerves.

The main nerves involved in this area are the auriculotemporal nerve, the auricular branch of the vagus, and maybe the greater auricular nerve. Wait, the auriculotemporal nerve is a branch of the mandibular division of the trigeminal nerve (CN V3). It supplies the skin over the temporoparietal region and the external ear, including the meatus. The auricular branch of the vagus (Arnold's nerve) innervates the posterior part of the external auditory meatus and the auricle. The greater auricular nerve comes from the cervical plexus (C2-C3) and supplies the skin over the parotid gland and the lower part of the ear.

So the sensory supply of the external auditory meatus is primarily from the auriculotemporal nerve (V3) and the auricular branch of the vagus. The correct answer would be a combination of these two. The question is asking for the sensory supply, so I need to check which options include these nerves. If the options are A to D, and one of them lists both, then that's the right answer.

Now, the incorrect options: if someone mistakes the facial nerve (CN VII) for sensory, that's wrong because CN VII is motor and taste. The lesser occipital nerve (C2) supplies the occipital region, not the ear canal. The glossopharyngeal nerve (CN IX) is more involved in the throat area. So each wrong option can be dismissed based on their usual territories.

The clinical pearl here is that the auriculotemporal nerve is a key player in this region, and the vagus's auricular branch is also important. Students often mix up the nerves of the ear, especially the auriculotemporal vs. greater auricular. Remembering that the auriculotemporal is part of the trigeminal (CN V) helps. Also, the vagus's auricular branch is involved in referred pain from the throat to the ear, which is a common exam point.

**Core Concept**
The sensory innervation of the external auditory meatus involves **auriculotemporal nerve (V3)** and **auricular branch of the vagus (Arnold’s nerve)**. These nerves supply sensation to the lateral and medial portions of the meatus, respectively, due to their anatomical distribution.

**Why the Correct Answer is Right**
The **auriculotemporal nerve** (a branch of CN V3) provides sensory innervation to the lateral third of the external auditory meatus. The **auricular branch of the vagus** (Arnold’s nerve) innervates the medial two-thirds of the meatus and the posterior auricle. This dual innervation arises from overlapping dermatomal contributions of cranial nerves V and X.

**Why Each Wrong Option is Incorrect**
**Option A:** *Facial nerve (CN VII)* is incorrect—it primarily mediates taste (via chorda tympani) and motor functions, not

✓ Correct Answer: D. Auriculotemporal nerve