This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of orbit, Lids and lacrimal apparatus, Subject name: Ophthalmology
Commonest cause for bilateral proptosis in children is - 
Select and explain. 
A. Cavernous hamangioma, B. Chloroma, C. Fibrous histiocytoma, D. Rhabdomyosarcoma
B: Chloroma
Answer: B: Chloroma 
Explanation: Most common cause of bilateral proptosis: In children : Neuroblastoma and leukemia (chloroma). In adults : Thyroid ophthalmopathy. Most common cause of unilateral proptosis: In children : Orbital cellulitis. In adults : Thyroid ophthalmopathy. Ref: A. K. Khurana 6thE pg404