<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 75-year-old man comes to the physician because of a 2-week history of sharp, stabbing pain in the lower back that radiates to the back of his left leg. He also has had a loss of sensitivity around his buttocks and inner thighs as well as increased trouble urinating the last week. Two years ago, he was diagnosed with prostate cancer and was treated with radiation therapy. Neurologic examination shows reduced strength and reflexes in the left lower extremity; the right side is normal. The resting anal sphincter tone is normal but the squeeze tone is reduced. Which of the following is the most likely diagnosis?? A: Brown-sequard syndrome, B: Anterior spinal cord syndrome, C: Central cord syndrome, D: Conus medullaris syndrome, E: Cauda equina syndrome,  <response>: Based on the description in the question stem, the key findings are:- Sharp, stabbing pain in the lower back radiating to the left leg - Loss of sensitivity around the buttocks and inner thighs- Increased trouble urinating- Reduced strength and reflexes in the left lower extremity- Normal right side- Normal resting anal sphincter tone but reduced squeeze toneThe unilateral sensory loss and motor weakness localized to the left lower extremity indicates a lateral spinal cord lesion, which is characteristic of Brown-Sequard syndrome. The reduced anal sphincter squeeze tone indicates sacral nerve roots are affected, pointing to a lesion at the level of the conus medullaris. This, along with the urinary symptoms and history of prostate cancer treated with radiation, makes conus medullaris syndrome the most likely diagnosis.E: Cauda equina syndrome 