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: Skin
[{'content': 'DOC in primary syphillis is \nSelect and explain. \nA. Coicosteroid, B. Oral Penicilline, C. Benzathine Penicilline, D. Crystalline Penicilline', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Benzathine penicillin', 'role': 'assistant'}]