This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
Is Lesser petrosal a branch of? 
Select and explain. 
A. Occulomotor nerve, B. Abducens nerve, C. Facial nerve, D. Glossopharyngeal nerve
D: Glossopharyngeal nerve
Answer: D: Glossopharyngeal nerve 
Explanation: The glossopharyngeal nerve gives the impoant branch-the tympanic branch also called the Jacobson&;s nerve. It leaves the inferior ganglion and enters middle ear through the tympanic canaliculussituated at the bony edge between the jugular foramen and carotid canal. It forms the tympanic plexus over the promontory of the middle ear.The tympanic plexus gives off the lesser petrosal nerve and twigs to tympanic cavity, auditory tube, and mastoid air cells.Reference: Textbook of anatomy, Head neck, and brain, Vishram Singh, 2nd edition, page no.345