This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': "Which of following drug's absorption is increased in gastric achlorhydria ? \nSelect and explain. \nA. Ketoconazole, B. Penicillin G, C. Chloramphenicol, D. Ciprofloxacin", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]