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: ENT
[{'content': 'Most common salivary gland tumor in children: \nSelect and explain. \nA. Lymphoma, B. Adenoid cystic Ca, C. Pleomorphic adenoma, D. Mucoepidermoid Ca', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The commonest benign tumor encountered is pleomorphic salivary adenoma accounting for approximately 30% of all pediatric salivary neoplasma. The majority occur within the parotid gland. Most common malignant tumor of salivary gland in childhood: Mucoeidermoid carcinoma, approximately 50% followed by acinic cell carcinoma (20%)', 'role': 'assistant'}]