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: Microbiology
[{'content': "Investigation of choice of diphtheria carrier is - \nSelect and explain. \nA. Throat Swab Culture, B. Gram's stain, C. Albe's stain, D. Zeil Nelson's stain", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Throat Swab Culture Carriers can be detected only by cultural methods --> Swabs are taken from nose and throat and it is examined by cultural methods for Diphtheria bacilli", 'role': 'assistant'}]