Thalassemia, a hereditary disorder, primarily impacts (a) Blood. It disrupts hemoglobin production, crucial for oxygen transport in red blood cells, leading to anemia. Symptoms range from mild to severe, depending on the type and severity of the condition. While complications like iron overload and organ damage may arise, it doesn’t directly affect the (b) Lungs or (c) Heart. However, severe cases may indirectly strain these organs due to chronic anemia. Nonetheless, the fundamental pathology of thalassemia revolves around blood disorders, making option (a) Blood the correct choice regarding its primary impact. Thus, the answer is not (d) None of these.