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
[{'content': 'A child is born with a single functional copy of a tumor suppressor gene. At the age of 5 years, the remaining normal allele is lost through mutation. As a result, the ability to control the transition from G1 to the S phase of the cell cycle is lost. Which of the following neoplasms is most likely to arise by means of this mechanism- \nSelect and explain. \nA. Retinoblastoma, B. Breast carcinoma, C. Adenocarcinoma of colon, D. Cerebral astrocytoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Robbins basic pathology 9th edition page no 182,Heading =RB gene Approximately 90 % of Retinoblastoma gene is sporadic, the remaining ones are familial, the predisposition to develop the tumor being transmitted as an autosomal dominant trait. Here all other conditions except Retinoblastoma are not associated with tumor suppresor gene defect.', 'role': 'assistant'}]