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: Pathology
[{'content': 'Organisms involved in pit and fissure caries: \nSelect and explain. \nA. Streptococcus mutans., B. Lactobacillus., C. Actinomyces., D. All of the above.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pit & fissure caries in initiated by a wide variety of organisms like S. mutans, Lactobacillus and Actinomyces species as they colonize in these retentive areas. However, only S.mutans (very significantly) & S. salivarius (by chance) have been proved to colonise smooth surfaces.', 'role': 'assistant'}]