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: Pathology
Which of the following statements is true ? 
Select and explain. 
A. Chronic myeloid leukemia occurs beyond 50 years of age, B. Hairy cell leukemia in less than 50 years has a good prognosis, C. Acute lymphoid leukemia in less than 1 year has a poor prognosis, D. Chronic lymphocytic leukemia occurs in less than 50 years of age
C: Acute lymphoid leukemia in less than 1 year has a poor prognosis
Answer: C: Acute lymphoid leukemia in less than 1 year has a poor prognosis 
Explanation: Ans. is 'c' i.e., Acute lymphoid leukemia in less than 1 year has a poor prognosis o Age <1 year and >10 years at the time of diagnosis of ALL is considered an adverse prognosis. o The median age at presentation of CML is approximately 50 years. The incidence of CML increases slowly with age until the middle foies where it stas to rise rapidly. o The median age of onset of hairy cell leukemia is 52 years. o CLL is considered to be mainly disease of the elderly with a median age at diagnosis of 70 years