A 45-year-old male with a 20-year history of heavy alcohol consumption presents with jaundice, fever (38.5°C), right upper quadrant tenderness, and hepatomegaly. Laboratory tests show AST 380 U/L, ALT 120 U/L, bilirubin 4.2 mg/dL, INR 1.8, and WBC 14,500/μL. A liver biopsy is performed. The structure marked **A** in the diagram is identified as an eosinophilic cytoplasmic inclusion within hepatocytes. Which of the following best describes the molecular composition of this inclusion?