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: Surgery
[{'content': 'Most common site of salivary gland stone \nSelect and explain. \nA. Submandibular gland, B. Parotid gland, C. Sublingual gland, D. Minor salivary glands', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Stones are common in submandibular gland due to thick secretions.', 'role': 'assistant'}]