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: ENT
Not a Boundary of Jackson's Triangle used in Tracheotomy 
Select and explain. 
A. Suprasternal notch, B. Lower edge thyroid cartilage, C. Outer border of Sterno cleitomastoid, D. Inner border of  Sterno cleitomastoid
C: Outer border of Sterno cleitomastoid
Answer: C: Outer border of Sterno cleitomastoid 
Explanation: None