This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematology, Subject name: Pediatrics
[{'content': 'The likely diagnosis in a child with limb pain and pancytopenia is \nSelect and explain. \nA. Aplastic anemia, B. Acute lymphocytic leukemia, C. Rheumatic fever, D. Rheumatoid ahritis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Child with acute lymphocytic leukemia presents with pallor, petechiae, infection(pancytopenia),. Reference: GHAI Essential pediatrics, 8th edition', 'role': 'assistant'}]