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
[{'content': 'Which of the following is a poor prognostic factor for childhood ALL. \nSelect and explain. \nA. Total Leukocyte count 4000-100,000, B. Age < 2 years, C. Testicular involvement, D. Blasts in peripheral smear', 'role': 'user'}, {'content': "Answer: C \nExplanation: Answer is C (Testicular involvement) Testicular involvement / enlargement is a typical poor prognostic factor for childhood ALL Age < 2 years versus Testicular Involvement Typically Age < 1 year is considered a poor prognostic factor Although Age < 2 year has been mentioned as a poor prognostic factor in ceain textbooks including Hoffman's Hematology (4th/1158) most textbooks use the criteria of Age < 1 year to define a poor prognostic factor Since testicular involvement provided amongst the option is an established poor prognostic factor, this is selected as the single best answer of choice.", 'role': 'assistant'}]