<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 35-year-old man, with a history of neurofibromatosis type 2 NF2 diagnosed 2 years ago, presents with hearing loss in the right ear and tinnitus. Patient says that symptoms have been gradually progressive. He has difficulty hearing speech as well as loud sounds. He also gives a history of occasional headaches and vertigo on and off for 1 month, which is unresponsive to paracetamol. His vitals include: blood pressure 11078 mm Hg, temperature 36.5C 97.8F, pulse 78min and respiratory rate 11min. Tuning fork tests reveal the following: Left RightRinnes test Air conduction bone conduction Air conduction bone conductionWeber test Lateralized to left ear Other physical examination findings are within normal limits. An MRI of the head is ordered which is as shown in image 1. A biopsy is done which shows cells staining positive for S100 but negative for glial fibrillary acidic protein GFAP. The histopathological slide is shown in image 2. What is the most likely diagnosis?? A: Glioblastoma multiforme, B: Hemangioblastoma, C: Schwannoma, D: Meningioma, E: Craniopharyngioma,  <response>: This is a patient with neurofibromatosis type 2 NF2 who presents with unilateral hearing loss, tinnitus, headaches, and vertigo. The key findings are the MRI showing a cerebellopontine angle tumor and the biopsy results being S100 positive and GFAP negative. The MRI shows a solid, enhancing tumor in the right cerebellopontine angle, likely originating from the 8th cranial nerve vestibulocochlear nerve. This location and imaging appearance is classic for vestibular schwannoma, which is the most common tumor seen in NF2.The biopsy of the tumor was positive for S100, which indicates neural crest origin, and negative for GFAP, which rules out astrocytic tumors like glioblastoma. This immunoprofile is consistent with schwannoma. The unilateral presentation also favors vestibular schwannoma over other tumors like meningioma or craniopharyngioma which are usually bilateral in NF2. Hemangioblastoma would also be unlikely given the location and biopsy results.Therefore, the most likely diagnosis is vestibular schwannoma, a benign nerve sheath tumor. This fits with the patients known diagnosis of NF2, which predisposes to bilateral vestibular schwannomas.C: Schwannoma 