This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Parafollicular cells (C-cells) in the thyroid are derived from 
Select and explain. 
A. Neural crest, B. Ultimobranchial body, C. Median bud of pharynx, D. Pharyngeal pouch
B: Ultimobranchial body
Answer: B: Ultimobranchial body 
Explanation: Cells of the ultimobranchial body give rise to the parafollicular, or C cells of the thyroid gland. These cells secrete calcitonin, a hormone involved in regulation of the calcium level in the bloodRef: Langman&;s Medical embryology; 12th edition; Chapter 17; Head and Neck