<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 27-year-old woman presents to your office complaining of right arm numbness and weakness. Her past medical history is unremarkable. Her family history, however, is significant for the unexpected death of both her parents at age 59 in a motor vehicle accident last week. On physical exam, her bicep, brachioradialis, and patellar reflexes are 2 bilaterally. CNS imaging shows no abnormalities. Which of the following is the most likely diagnosis?? A: Conversion disorder, B: Vitamin B12 deficiency, C: Amyotrophic lateral sclerosis, D: Arnold-Chiari malformation, E: Multiple sclerosis,  <response>: This is a clinical case scenario involving a 27-year-old woman with right arm numbness and weakness. The key findings are normal past medical history, recent death of parents in MVA, normal reflexes, and normal CNS imaging. The differential diagnosis includes conversion disorder, vitamin B12 deficiency, ALS, Arnold-Chiari malformation, and multiple sclerosis. Conversion disorder is a functional neurological disorder that can present with neurological symptoms like numbnessweakness in the setting of psychological stressors. The recent traumatic death of her parents is a significant psychological stressor that supports this diagnosis. Vitamin B12 deficiency can cause neurological symptoms but reflexes are often decreased, and this patient has normal reflexes. ALS and MS would show abnormalities on CNS imaging. Arnold-Chiari malformation may cause arm numbness but imaging was normal.Based on the normal reflexes and imaging along with the preceding psychological trauma, conversion disorder is the most likely diagnosis.A: Conversion disorder 