**Core Concept**
Pernicious anaemia is a type of megaloblastic anaemia caused by a deficiency of vitamin B12 due to autoimmune gastritis. This condition leads to mucosal atrophy in the stomach, which is a precursor to gastric carcinoma.

**Why the Correct Answer is Right**
Pernicious anaemia is associated with a higher risk of developing gastric carcinoma due to chronic mucosal atrophy and intestinal metaplasia. The autoimmune gastritis that causes pernicious anaemia leads to the loss of parietal cells, which are responsible for producing intrinsic factor, a protein necessary for vitamin B12 absorption. This results in a decrease in gastric acid production and an increase in the risk of gastric carcinoma.

**Why Each Wrong Option is Incorrect**
**Option A:** Iron-deficiency anaemia is a common cause of anaemia, but it is not typically associated with an increased risk of gastric carcinoma. Iron deficiency is more commonly linked to colorectal cancer.
**Option B:** Thalassemia major is a genetic disorder that leads to severe anaemia, but it is not a risk factor for gastric carcinoma. Thalassemia major is associated with other complications such as bone deformities and heart problems.
**Option C:** Sideroblastic anaemia is a type of anaemia characterized by the accumulation of iron in the mitochondria of red blood cells. While it can be caused by various factors, including genetic mutations and exposure to toxins, it is not typically associated with an increased risk of gastric carcinoma.

**Clinical Pearl / High-Yield Fact**
Pernicious anaemia is often seen in individuals with a family history of autoimmune disorders, such as type 1 diabetes and Hashimoto's thyroiditis.

**Correct Answer:** C. Pernicious anaemia is a risk factor for the development of gastric carcinoma.