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
Sjogren's syndrome refers to disease of - 
Select and explain. 
A. Parotid glands, B. Thyroid disease, C. Parathyroid glands, D. Multiple endocrine neoplasia
A: Parotid glands
Answer: A: Parotid glands 
Explanation: None