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': 'The malunion of supracondylar fracture of the humerus most commonly leads to - \nSelect and explain. \nA. Flexion deformity, B. Cubitus varus, C. Cubitus valgus, D. Extension deformity', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cubitus varus, also known as a "gunstock deformity", is the most common complication of supracondylar fracture humerus, due to malunion.', 'role': 'assistant'}]