This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Aplastic Anemia, Subject name: Pathology
A 30-year-old woman complains of recent easy fatigability, bruising, and recurrent throat infections. Physical examination reveals numerous petechiae over her body and mouth. Abnormal laboratory findings include hemoglobin of 6 g/dL, WBC of 1,500/mL, and platelets of 20,000/mL. The bone marrow is hypocellular and displays increased fat. What is the appropriate diagnosis? 
Select and explain. 
A. Aplastic anemia, B. Iron-deficiency anemia, C. Megaloblastic anemia, D. Leukemia
A: Aplastic anemia
Answer: A: Aplastic anemia 
Explanation: - Given features suggests the diagnosis of Aplastic anemia - Aplastic anemia is a disorder of pluripotent stem cells causing bone marrow failure resulting in hypocellular bone marrow & pancytopenia - Most cases are idiopathic. - Iron-deficiency anemia (choice B) and megaloblastic anemia (choice C) are not characterized by a hypoplastic bone marrow.