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': 'The preferred treatment option for primary syphilis is - \nSelect and explain. \nA. Injection benzathine pencillin 2.4 million units IM single dose, B. Injection benzathine pencillin 2.4 million units IM once a week for 3 weeks, C. Cap. doxycycline 100 mg orally twice a day for 2 weeks, D. Tab. azithromycin 2 gm single dose', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e.,Injection benzathine pencillin 2.4 million units IM single dose", 'role': 'assistant'}]