This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb, Subject name: Anatomy
[{'content': 'The synol bursa which commonly communicates with the cavity of the shoulder joint is \nSelect and explain. \nA. Subscapular bursa, B. Infraspinatus bursa, C. Subacromial bursa, D. Supraspinatus bursa', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The joint cavity communicates with the subscapular bursa, with the synol sheath for the tendon of the long head of the biceps brachii, and often with the infraspinatus bursa.Ref: BD Chaurasia; Volume 1; 6th edition; Page no: 144', 'role': 'assistant'}]