You are answering a USMLE-style medical question. Question: A 32-year-old man comes to the physician for a pre-employment examination. He recently traveled to Guatemala. He feels well but has not seen a physician in several years, and his immunization records are unavailable. Physical examination shows no abnormalities. Serum studies show: Anti-HAV IgM Positive Anti-HAV IgG Negative HBsAg Negative Anti-HBs Positive HBcAg Negative Anti-HBc Negative HBeAg Negative Anti-HBe Negative Anti-HCV Negative Which of the following best explains this patient's laboratory findings?" Options: A) Active hepatitis A infection B) Previous hepatitis A infection C) Chronic hepatitis B infection D) Chronic hepatitis C infection Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.