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': 'Sialography is used to detect anomaly of: \nSelect and explain. \nA. Salivary duct only, B. Salivary gland, C. Salivary gland & duct, D. Salivary gland tumours', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]