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: Medicine
A child presents with seborrheic dermatits, lytic skull lesions, ear discharge and hepatosplenomegaly, likely diagnosis - 
Select and explain. 
A. Leukemia, B. Lymphoma, C. Histiocytosis X, D. Multiple myeloma
C: Histiocytosis X
Answer: C: Histiocytosis X 
Explanation: None