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': 'Which egg does not float in a saturated solution of saline? \nSelect and explain. \nA. Ankylostoma eggs, B. Trichuris eggs, C. Unfertilized eggs of ascaris, D. Fertilized eggs of ascaris', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]