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': 'Cholera toxin binds to which receptors in intestine: \nSelect and explain. \nA. Sphingosine through A subunit, B. Sphingosine through B subunit, C. GM1 gangliosides through A subunit, D. GM1 gangliosides through B subunit', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is. 'd' i. e., GM1 gangliosides through B subunit", 'role': 'assistant'}]