<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 presents to his primary care provider complaining of dull pain in his scrotum and lower back pain over the last 3 months. He is a computer engineer working in a private IT company. He had an uncomplicated appendectomy at the age of 22 years, but is otherwise without a significant past medical history. He smokes 23 cigarettes on weekends and drinks alcohol occasionally. He is sexually active with his wife. Today his heart rate is 90min and blood pressure is 13276 mm Hg. Scrotal examination reveals a firm, small and painless nodule on the left testicle. Scrotal ultrasound reveals a 0.9 x 0.5 cm irregular, non-cystic mass. He undergoes a left radical orchiectomy and histopathological examination reveals uniform tumor cells with abundant clear cytoplasm and distinct cell borders, consistent with a seminoma. Subsequent PETCT scans show supraclavicular and para-aortic lymph node involvement. Which is the next and most appropriate step in the management of this patient?? A: Observation, B: Chemotherapy, C: Radiotherapy, D: Surgery, E: Immunotherapy,  <response>: This is a question about testicular cancer management. The patient is a 35-year-old man who presented with scrotal and back pain. He underwent a left radical orchiectomy and was found to have a seminoma on pathology. PETCT showed lymph node involvement. The next step in management would be to treat the metastatic disease.B: Chemotherapy 