This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Investigation of choice in the early phase of renal transplant \nSelect and explain. \nA. IVP, B. Retrograde cystourethrogram, C. Ultrasonogram, D. CT scan', 'role': 'user'}, {'content': 'Answer: C \nExplanation: • Vascular complications after renal transplantation are low, presents during the first week after transplantation with sudden pain and swelling at the site of the graft.\n• Diagnosis is confirmed by Doppler ultrasonography.\n• Urgent surgical exploration is indicated and, in most cases, transplant nephrectomy\xa0is required.', 'role': 'assistant'}]