**Core Concept**
The lacrimal gland is a compound gland that produces tears to lubricate and protect the eye. The secretomotor nerve fibres that stimulate the lacrimal gland are parasympathetic in nature, originating from the central nervous system and acting on specific receptors in the gland.

**Why the Correct Answer is Right**
The lacrimal gland is supplied by the parasympathetic branch of the autonomic nervous system. The preganglionic neurons originate from the lacrimatory nucleus in the pons, synapsing with postganglionic neurons in the pterygopalatine ganglion (also known as the sphenopalatine ganglion). The postganglionic fibres then travel to the lacrimal gland, where they stimulate the secretion of tears by acting on muscarinic receptors.

**Why Each Wrong Option is Incorrect**
* **Option A:** The ciliary ganglion is involved in controlling the sphincter pupillae and ciliary muscles, not the lacrimal gland.
* **Option B:** The otic ganglion is associated with the parotid gland, not the lacrimal gland.
* **Option D:** The submandibular ganglion is involved in the innervation of the submandibular and sublingual salivary glands.

**Clinical Pearl / High-Yield Fact**
The pterygopalatine ganglion is a key autonomic ganglion that supplies parasympathetic fibres to the lacrimal gland, as well as sympathetic fibres to the blood vessels in the nasal cavity and the lacrimal gland.

**Correct Answer: C. Pterygopalatine ganglion.**