question: Q:A 60-year-old man comes to the physician for a routine health maintenance examination. Over the past year, he has had problems initiating urination and the sensation of incomplete bladder emptying. He has a history of hypertension and hypercholesterolemia. He has smoked one pack of cigarettes daily for the past 40 years. He does not drink alcohol. His medications include lisinopril, atorvastatin, and daily aspirin. Vital signs are within normal limits. Physical examination shows a pulsatile abdominal mass at the level of the umbilicus and a bruit on auscultation. Digital rectal examination shows a symmetrically enlarged, smooth, firm, nontender prostate with rubbery texture. Laboratory studies are within normal limits. Which of the following is the most appropriate next step in management?? 
  {'A': 'CT scan of the abdomen with contrast', 'B': 'Aortic arteriography', 'C': 'Prostate biopsy', 'D': 'PSA level testing', 'E': 'Abdominal ultrasonography'},