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': 'Beta lactam antibiotics act by inhibiting \nSelect and explain. \nA. Cell wall synthesis, B. Protein synthesis, C. RNA synthesis, D. DNA synthesis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]