This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of the Aorta, Subject name: Medicine
Notching of ribs occurs in all EXCEPT: 
Select and explain. 
A. Coarctation of aorta, B. Neurofibromatosis, C. Hypothyroidism, D. Osteogenesis imperfecta
C: Hypothyroidism
Answer: C: Hypothyroidism 
Explanation: ANSWER: (C) HypothyroidismREF: Chapman page 57CAUSES OF RIB NOTCHINGSuperiorInferior* Polio* Coarctation of aorta* Osteogenesis imperfecta* Pulmonary oligemia/A-V malformation* Restrictive lung disease* Aortic thrombosis* Neurofibromatosis* Subclavian obstruction* Marfan's syndrome* Taussig blalock operation* Connective tissue disorders - RA, scleroderma, SEE* Hyperparathyroidism