This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Childhood Tumors, Subject name: Pediatrics
A malignant tumor of childhood that frequently metastasizes to bone marrow most often is: 
Select and explain. 
A. Wilms' tumor, B. Neuroblastoma, C. Adrenal gland tumors, D. Granulosa cell tumor of ovary
B: Neuroblastoma
Answer: B: Neuroblastoma 
Explanation: b. Neuroblastoma(Ref: Indian J Hematol Blood Transfus. 2011 ;27(2):93-95)The malignancies of prostate, breast, lungs, kidney & thyroid in adults and neuroblastoma and rhabdomyosarcoma in children are the primary tumors which frequently involve bone marrow.