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': 'All of the following lab tests can be used to distinguish Streptococcus mutans from other oral streptococci, except \nSelect and explain. \nA. Gram staining, B. Fermentation of mannitol and sorbital, C. Production of intracellular and extracellular adherent polysaccharide, D. Colony morphology on saliva agar', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]