All of the following can cause megakaryocytic thrombocytopenia, except-

Answer is C (Aplastic Anemia): Amegakaryocytic Aplastic anemia is characterized by decreased or absent megakaryocytes (platelet precusors) and indicates a defect in production of platelets. Amongst the options provided only aplastic anemia is associated with decreased production of platelets and causes amegakaryocytic thrombocytopenia. The most common causes of thrombocytopenia with decreased number of megakaryocytes in marrow are aplastic anemia, marrow. fibrosis and infiltration of marrow with malignant cells (Harrison)