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': 'Cross-resistance can be one way or two way, one-way resistance can be seen in: \nSelect and explain. \nA. Neomycin and streptomycin, B. Tetracycline and doxycycline, C. Sulphadiazine and sulphadoxine, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Organisms that develop resistance to an antimicrobial agent may also show resistance to other\xa0 chemically related AMAs. The cross-resistance among AMAs could either be one-way or two-way.\xa0 Cross-resistance among tetracyclines and sulphonamides is usually ‘two-way’.', 'role': 'assistant'}]