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
Upper boundary of quadrangular space is formed by: 
Select and explain. 
A. Teres major, B. Teres minor, C. Long head of triceps, D. Surgical neck of humerus
B: Teres minor
Answer: B: Teres minor 
Explanation: Boundaries of quadrangular spaceAbove/superior: the subscapularis and teres minorBelow/inferior: the teres majorMedially: the long head of the triceps brachiiLaterally: the surgical neck of humerus