This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pelvis & Injuries, Subject name: Orthopaedics
[{'content': "Telescopic test is useful to diagnosis: \nSelect and explain. \nA. Perthe's disease, B. Intracapsular fracture neck of femur, C. Malunited Trochanteric fracture, D. Ankylosis of hip joint", 'role': 'user'}, {'content': 'Answer: B \nExplanation: (b) Intracapsular fracture neck of femur- Positive Telescopy test indicates instability of hip joint such as: old unreduced posterior dislocation, loss of neck and or head in old fractures neck femur and paralytic hip.', 'role': 'assistant'}]