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': 'Drug of choice for chylamydial trachomatis is: March 2007 \nSelect and explain. \nA. Penicilin, B. Erythromycin, C. Vancomycin, D. Azithromycin', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. D: Azithromycin Because of higher efficacy, better gastric tolerance and convenient once a day dosing, azithromycin is now preferred over erythromycin as first choice drug for infections such as: Legionnaires' pneumonia Chlamydia trachomatis Donovanosis caused by calymmatobacterium granulomatis Chancroid and PPNg urethritis.", 'role': 'assistant'}]