This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
A child is born with a single functional copy of a TSG. At the age of 5, the remaining normal allele is lost through mutation. As a result, the ability to control transition from G1 to S phase of cell cycle is lost. Which neoplasm is mot likely to arise in this child? 
Select and explain. 
A. Retinoblastoma, B. Breast carcinoma, C. Adenocarcinoma colon, D. Cerebral astrocytoma
A: Retinoblastoma
Answer: A: Retinoblastoma 
Explanation: .