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: Surgery
[{'content': 'Which of the given test is used for assessing posterior glenohumeral instability? \nSelect and explain. \nA. Jerk test, B. Crank test, C. Fulcrum test, D. Sulcus test', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Common posterior instability tests include the jerk test, posterior stress test, Kim test, and load and shift test. Crank test is for superior labral pathology which is similar to the McMurray test for the knee. The crank test attempts to catch labrum tears between the two joint surfaces. Both the "hop" test and the "fulcrum" test are helpful in making the diagnosis of a femoral shaft stress fracture. The sulcus test evaluates inferior instability of the humeral head. Ref: Shoulder edited by Richard L.Angelo, 2010, Page 118.', 'role': 'assistant'}]