A 45-year-old man is found to have a duodenal ulcer on endoscopy. Biopsy is positive for Helicobacter pylori. He has no drug allergies and takes no other medications. What is the most appropriate first-line eradication regimen in Australia?AProton pump inhibitor plus amoxicillin plus clarithromycin for 7-14 daysBProton pump inhibitor plus metronidazole aloneCClarithromycin monotherapy for 7 daysDAmoxicillin and metronidazole without acid suppressionENo treatment is required if asymptomaticCheck my answer