This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'Referred otalgia from base of tongue or oropharynx is carried by nerve: \nSelect and explain. \nA. Cranial nerve V, B. Cranial nerve VII, C. Cranial nerve IX, D. Cranial nerve X', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The Jacobson nerve, tympanic branch of glossopharyngeal nerve (cranial nerve IX) directly innervates the ear but also has pharyngeal, lingual, and tonsillar branches to supply the posterior one-third poion of the tongue, tonsillar fossa, pharynx, eustachian tube, and parapharyngeal and retropharyngeal spaces. So any pathology involving those areas can lead to referred otalgia. Must know: Referred Otalgia: the source of the pain does not reside within the ear but, rather it originates from a source distant from the ear hence it is called as "referred otalgia". Any pathology residing within the sensory net of cranial nerves V, VII, IX, and X and upper cervical nerves C2 and C3 can potentially cause referred otalgia. Ref: Diseases of Ear Nose & Throat, by P L Dhingra, 2nd edition.', 'role': 'assistant'}]