Before this question will be answered, it is important that microcytic anaemia is understood. This is a condition wherein there is a presence of hypochromic or pale red blood cells. The lack of iron can cause this type of anemia. The answer to this is D. The other conditions can be caused by microcytic anemia but pancytopenia can only be caused by megaloblastic anemia.
This is usually caused by having leukemia. Pancytopenia means that all of the components of the blood are deficient. In order to determine the actual cause of pancytopenia, getting a sample of the bone marrow is going to be required. This is a painful test for a lot of people.