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
A2 concentration in thalassemia trait is ? 
Select and explain. 
A. 1, B. 1-2.5, C. 2.5-3.5, D. >3 .5
D: >3 .5
Answer: D: >3 .5 
Explanation: Ans. is 'd' i.e., > 3.5 T. Major Intermedia T. Minor J Genetics Homozygous Double Heterozygot es heterozygotes Hb F 30-90% (20-100%) 0-5% ) HbA2 < 3.5% <3.5% 3.6 -8%