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: Pediatrics
A child presents with seborrheic dermatitis, sinusitis and chronically draining ears. On examination child has failure to thrive with hepatosplenomegaly and exophthalmos. Probable diagnosis is 
Select and explain. 
A. Histiocytosis-X, B. Wegener's granulomatosis, C. Chronic granulomatous disease, D. Chediak-Higashi syndrome
A: Histiocytosis-X
Answer: A: Histiocytosis-X 
Explanation: Ans. a. Histiocytosis-X