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: Ophthalmology
Blue sclera is seen in –a) Alkaptonuriab) Osteogenesis imperfectac) Ehler – Danlos syndromed) Kawasaki syndrome 
Select and explain. 
A. a, B. c, C. bc, D. ad
C: bc
Answer: C: bc 
Explanation: Causes of blue sclera are Osteogenesis iniperfecta, Marfan syndrome, Ehler - Danlos syndrome, Pseudoxanthoma elasticum.