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: Gynaecology & Obstetrics
[{'content': 'Which of the following cannot be detected by wet film? \nSelect and explain. \nA. Candida, B. Trichomonas, C. Chlamydia, D. Bacterial vaginosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: diagnosis of chlamydial infections\n\nnucleic acid amplification by PCR\xa0\nChlamydial Antigenby ELISA,\nTissue cultures', 'role': 'assistant'}]