This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Embryology of Ear and Malformations, Subject name: ENT
All are derived from branchial arch EXCEPT? 
Select and explain. 
A. Ultimobranchial body, B. Stapes, C. Laryngeal cartilage, D. Mandible
A: Ultimobranchial body
Answer: A: Ultimobranchial body 
Explanation: Ans. (a) Ultimobranchial bodyRef: Inderbir Singh's Embroyology, 7th ed. /119-120* In humans, the ultimobranchial body is an embryological structure that gives rise to the calcitonin-producing cells--also called parafollicular cells or C cells--of the thyroid gland.* In humans, this body is a derivative of the ventral recess of the fourth pharyngeal pouch.* Stapes: from 2nd Branchial arch* Laryngeal cartilage: from 6th branchial arch* Mandible: from 1st branchial arch