This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Medicine
[{'content': 'True about a-thalassemia trait - \nSelect and explain. \nA. Increased HbF, B. Increased HbA, C. Microcytosis, D. Severe anemia', 'role': 'user'}, {'content': 'Answer: C \nExplanation: <p>Alpha thalassemia trait occurs by deletion of two of the four alpha chain genes in homozygous called homozygous alpha thalassemia or in double heterozygous form termed heterozygous alpha thalassemia .Blood film shows microcytic & hypochromic red cell morphology but no evidence of hemolysis or anemia.</p><p>Reference :Harsh mohan textbook of pathology sixth edition pg no 321.</p>', 'role': 'assistant'}]