Ans. a (Glossopharyngeal). (Ref. BD Chaurasia, Anatomy, Vol 3, 2nd/pg.215; Harrison-18lh/29-4)Papillae in tongue.PapillaeLocationNerve supplyCircumvallate (posterior) papillaePresent on anterior 2/3rd of the tongue, in front of sulcus terminalis.Glossopharyngeal nerve, which is the nerve of taste for posterior l/3rd of tongue.Fungiform (anterior) and filiform or Foliate (lateral) papillaeFiliform Papillae are numerous on anterior 2/3rd of tongue.Fungiform are scattered on sides & apex.Both are supplied by lingual nerve (general sensations) & chorda tympani (taste).Taste information is sent to the brain via three cranial nerves (CNs): CN VII (the facial ner'e, which involves the intermediate nerve with its branches, the greater petrosal and chorda tympani nerves); CN IX (the glossopharyngeal nerve); and CN X (the vagus nerve). CN VII innervates the anterior tongue and all of the soft palate, CN IX innervates the posterior tongue, and CN X innervates the laryngeal surface of the epiglottis, the larynx, and the proximal portion of the esophagus. The mandibular branch of CN V (V3) conveys somatosensory information (e.g., touch, burning, cooling, irritation) to the brain. Although not technically a gustatory nerve, CN V shares primary nerve routes with many of the gustatory nerve fibers and adds temperature, texture, pungency, and spiciness to the taste experience. The chorda tympani nerve is notable for taking a recurrent course through the facial canal in the petrosal portion of the temporal bone, passing through the middle ear, then exiting the skull via the petrotympanic fissure, where it joins the lingual nerve (a division of CN V) near the tongue. This nerve also carries parasympathetic fibers to the submandibular and sublingual glands, whereas the greater petrosal nerve supplies the palatine glands, thereby influencing saliva production.