**Core Concept**
The Wharton's duct is a vital anatomical landmark in the neck, serving as the path for the submandibular gland's secretions to drain into the oral cavity. The proximity of nerves to this duct is crucial for surgical procedures involving the submandibular gland.

**Why the Correct Answer is Right**
The lingual nerve, a branch of the mandibular division of the trigeminal nerve (CN V3), lies in close proximity to the Wharton's duct. This is because the lingual nerve runs posterior to the duct, providing sensory innervation to the anterior two-thirds of the tongue. The lingual nerve's close relationship with the Wharton's duct makes it a significant consideration during surgeries involving the submandibular gland.

**Option A:** The hypoglossal nerve (CN XII) primarily innervates the extrinsic and intrinsic muscles of the tongue and does not have a close relationship with the Wharton's duct.

**Option C:** The chorda tympani nerve, a branch of the facial nerve (CN VII), carries taste fibers from the anterior two-thirds of the tongue and also has a close relationship with the submandibular gland but is not as intimately associated with the Wharton's duct as the lingual nerve.

**Option D:** The facial nerve (CN VII) is responsible for controlling the muscles of facial expression and does not have a direct relationship with the Wharton's duct.

**Clinical Pearl / High-Yield Fact**
When performing surgeries involving the submandibular gland, it is essential to identify and preserve the lingual nerve to prevent postoperative sensory deficits in the anterior two-thirds of the tongue.

**✓ Correct Answer: B. Lingual**