21 year old male presents with anemia and mild hepatosplenomegaly

A 21 year old male presents with anemia and mild hepatosplenomegaly. His hemoglobin is 5 gm/dL history of single blood transfusion is present till date. Most probable diagnosis is :

a) Thalassemia major
b) Thalassemia minor
c) Thalasseniia intermedia
d) Autoimmune hemolytic anemia

Correct answer : d) Autoimmune hemolytic anemia