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: Pathology
Clavicle is absent in: 
Select and explain. 
A. Osteogenesis imperfecta, B. Cleidocranial dysostosis, C. Fibrous dysplasia, D. Osteopetrosis
B: Cleidocranial dysostosis
Answer: B: Cleidocranial dysostosis 
Explanation: Cleidocranial Dysplasia
(Marie and Sainton’s disease, Scheuthauer-Marie-Sainton syndrome, mutational dysostosis).
A congenital disorder of bone formation manifested with clavicular hypoplasia or agenesis with a narrow thorax, which allows approximation of the shoulders in front of the chest.