This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
[{'content': 'Active thyroid follicles are lined by which type of epithelium? \nSelect and explain. \nA. Columnar, B. Cuboidal, C. Squamous, D. Pseudostratified squamous', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The thyroid follicle is the structural and functional unit of the thyroid gland. The thyroid gland stores its secretory substances in the lumina of follicles. These cyst-like structures, ranging from 0.2 to 0.9 mm in diameter, are composed of a simple cuboidal epithelium, composed of follicular cells surrounding a central colloid-filled lumen and contacting the colloid as well as parafollicular cells (clear cells; C cells) that are located at the periphery of the follicle and do not contact the colloid.Ref: Textbook of Histology, 4thedition; Chapter 13; Endocrine system; Page no: 355', 'role': 'assistant'}]