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': 'Post Poliomyelitis, a patient has grade H power in Gastrocnemius, grade HI is Peroneus, grade IV in Tibialis Anterior. The deformity is - \nSelect and explain. \nA. Calcaneovalgus, B. Equino varus, C. Calcaneo varus, D. Genu valgus', 'role': 'user'}, {'content': "Answer: C \nExplanation: Gastrocnemius (plantar flexor) is weak with grade II power, while tibialis anterior (dorsi flexor) is strong with grade IV power, Therefore foot is thrown into 'dorsiflexion' or 'calcaneo' position.\nPeronii (everters) provide valgus strain, while Tibialis anterior provides a varus strain. Because peronii are weak here (grade III), the foot goes into varus position.", 'role': 'assistant'}]