This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuromuscular disorders, Subject name: Orthopaedics
[{'content': "All are true regarding pes planus except: \nSelect and explain. \nA. There is collapse of medial longitudinal arch, B. The heel becomes valgus and foot pronates at the subtalar-mid complex joint, C. Jack's test differentiates between flexible and rigid deformity, D. One of the common type of tarsal coalition is calcaneonavicular & it is autosomal recessive", 'role': 'user'}, {'content': "Answer: D \nExplanation: PES PLANUS (FLAT FOOT) Flat foot refers to obliterated medial longitudinal arch Heel is often in valgus called as planovalgus Pes Planus is of 2 types: (Differentiated by Jack's test) Flexible: Disappears on non-weight bearing. Management is conservative Rigid: Due to congenital veical talus or RA or infection or tarsal coalition or tibialis posterior dysfunction. They often require surgical intervention Tarsal Coalition is autosomal dominant fusion of tarsal bones (talocalcaneal, calcaneonavicular and talonavicular)", 'role': 'assistant'}]