Question

a deficiency of b12 caused by lack of intrinsic factor due to the development of chronic atrophic gastritis is called:
aplastic anemia
myelodysplastic syndrome
hemolytic anemia
pernicious anemia

Explanation:

Pernicious anemia is specifically associated with a deficiency of vitamin B12 due to a lack of intrinsic factor, often resulting from chronic atrophic gastritis. Aplastic anemia involves bone marrow failure. Myelodysplastic syndrome is a group of disorders where bone marrow doesn't produce enough healthy blood cells. Hemolytic anemia is due to the destruction of red blood cells.

Answer:

Pernicious anemia