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: Anatomy
Isthmus of thyroid gland is across tracheal rings: 
Select and explain. 
A. 2nd - 4th, B. 3rd - 5th, C. 5th and 6th, D. 4th only
A: 2nd - 4th
Answer: A: 2nd - 4th 
Explanation: The isthmus of the thyroid gland extends across the midline in front of the 2nd, 3rd, and 4th tracheal rings.