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: Medicine
[{'content': 'A 56-year-old man presents to his internist with jaundice. The patient is receiving no medication and his only symptomatic complaint is mild fatigue over the past 2 months. Physical examination is remarkable only for the presence of scleral icterus. The patient has no significant past medical history. Analysis of serum chemistry reveals the following- SGOT : 0.58 microkat/L (35U/L) SGPT : 0.58 microkat/L (35U/L), Total bilirubin: 91.7 micron mol/L (7mg/dL) Direct Bilirubin:85.5 micron mol/L (5 mg/dL) Alkaline phosphatase : 12 micron kat/L(720 U/L) Which of the following is the next most appropriate diagnostic step? \nSelect and explain. \nA. Ultrasound, B. Liver biopsy, C. Review of peripheral blood smear, D. Endoscopic retrograde cholangiopan creatography (ERCP)', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]