<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 5-year-old boy is brought to the physician because of early morning headaches for the past 6 months. During this period, he has had severe nausea and occasional episodes of vomiting. For the past month, he has had difficulty walking and intermittent double vision. He was born at term and has been healthy apart from an episode of sinusitis 8 months ago that resolved spontaneously. He is at the 60th percentile for height and 50th percentile for weight. His temperature is 37.1C 98.8F, pulse is 80min, and blood pressure is 10564 mm Hg. Examination shows normal muscle strength and 2 deep tendon reflexes bilaterally. He has a broad-based gait and impaired tandem gait. Fundoscopy shows bilateral swelling of the optic disc. There is esotropia of the left eye. Which of the following is the most likely diagnosis?? A: Optic glioma, B: Schwannoma, C: Hemangioblastoma, D: Meningioma, E: Medulloblastoman,  <response>: Based on the information provided, this appears to be a case involving a 5 year old boy with symptoms of early morning headaches, nausea, vomiting, difficulty walking, double vision, and findings of swollen optic discs and impaired gait. The key findings are the young age of onset, headaches, vision changes, and cerebellar signs pointing to a posterior fossa lesion. The differential diagnosis includes various pediatric brain tumors. Optic gliomas are the most common brain tumors in children and often present with vision changes. Medulloblastoma is the most common malignant brain tumor in children and arises in the cerebellum, causing headaches, ataxia, and hydrocephalus. Schwannomas and meningiomas are less likely in a child. Hemangioblastomas can cause similar symptoms but are very rare in children.Given the vision changes and cerebellar findings, the most likely diagnosis is a posterior fossa tumor like medulloblastoma. Optic glioma would not explain the cerebellar findings.E: Medulloblastoma 