A 32-year-old man is evaluated for a 2-week history of nausea, malaise, low-grade fever, vomiting and jaundice. Other than having multiple sex partners, he has no other significantmedical history and takes only ibuprofen for headache and fever. On physical examination,temperature is 37.6°C (99.74). blood pressure is 110/75 mm Hg, pulse rate is 90/min, and respiration rate is 22/min. Examination reveals scleral icterus, jaundice, hepatomegaly, asterixis, and somnolence. There are no stigmata of chronic liver disease. Bilirubin (total) 17.5 mg/dL (299.2 umol/L) INR 2.3 Aspartate aminotransferase 8790 U/L Alanine aminotransferase 7650 U/L Hepatitis B surface antigen Positive Hepatitis B core antigen (IgM) Positive Hepatitis C virus RNA Negative Hepatitis A IgM antibody Negative HepatitisA IgG antibody Positive Ultrasonography shows hepatomegaly and increased echogenicity, a normal spleen, and perihepatic ascites. There is no ductal dilatation. Which of the following is the most iikely diagnosis?