This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Salivary Glands, Subject name: Pathology
Most common primary malignant tumour of parotid gland 
Select and explain. 
A. Wahin tumour, B. Mucoepidermoid Cancer, C. Acinic cell Cancer, D. Adenoidcystic carcinoma
B: Mucoepidermoid Cancer
Answer: B: Mucoepidermoid Cancer 
Explanation: - Most common primary malignant tumor of parotid gland is Mucoepidermoid carcinoma - Mucoepidermoid carcinoma Malignant neoplasm of variable biological aggressiveness Composed of a mixture of squamous, mucous secreting & intermediate cells.