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: Orthopaedics
[{'content': 'Pipkin fracture is defined as - \nSelect and explain. \nA. Head of radius fracture, B. Head of femur fracture, C. Fracture dislocation of ankle, D. Fracture neck of femur', 'role': 'user'}, {'content': "Answer: B \nExplanation: Pipikin's classification of femoral head fracture\nType I:\xa0Femoral head fracture inferior (caudal) to fovea\nType II:\xa0Femoral head fracture superior (cephalad) to fovea\nType III:\xa0Femoral head fracture with associated femoral neck fracture\nType IV :\xa0Type I, II or III with associated acetabular fracture", 'role': 'assistant'}]