You are answering a USMLE-style medical question. Question: A 48-year-old homeless male is brought to the emergency department, by the police, for altered mental status. Past medical records are unavailable. A physical exam on admission reveals scleral icterus and a flapping tremor of the wrists during extension. The patient is admitted to the hospital and his treatment is started after appropriate investigation. The next morning on rounds, he complains of eleven episodes of diarrhea and near-constant flatulence overnight. His mental status has improved and his hand tremor has resolved. Which of the following medications did this patient most likely receive after admission? Options: A) Thiamine B) Lactulose C) Naloxone D) Rifaximin Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.