This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
[{'content': 'Which of the following structure passes through the triangular interval of the arm? \nSelect and explain. \nA. Radial nerve, B. Axillary nerve, C. Median nerve, D. Ulnar Nerve', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Radial nerve RegionBoundariesContentsUpper triangular space of armSuperior: Teres minorInferior : Teres majorLateral: Long head of tricepsCircumflex scapular arteryLower triangular space of armSuperior: Teres majorMedial: Long head of tricepsLateral; Shaft of humerusRadial nerveProfunda brachii vesselsQuadrangular space of armSuperior: Teres minor, subscapularis, joint capsuleInferior :Teres majorMedial: Long head of tricepsLateral: Surgical neck of humerusAxillary nervePosterior circumflex humeral vessels", 'role': 'assistant'}]