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 the following is true about penicillin: \nSelect and explain. \nA. Acid-resistant., B. Excreted mainly through the kidney., C. More concentrated in prostatic fluid., D. Is a broad-spectrum antibiotic.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]