**Core Concept**
Linitis plastica, also known as Brinton's disease or leather bottle stomach, is a condition characterized by the thickening and rigidity of the stomach wall due to diffuse infiltration of malignant cells.

**Why the Correct Answer is Right**
Diffuse carcinoma of the stomach, particularly the signet ring cell type, is the primary cause of linitis plastica. The cancer cells infiltrate the gastric wall, leading to fibrosis and thickening, which results in a rigid and non-distensible stomach. This condition is often associated with gastric lymphoma, which can also cause similar changes in the stomach wall.

**Why Each Wrong Option is Incorrect**
**Option A:** Hiatus hernia is a condition where the stomach bulges up into the chest through an opening in the diaphragm, but it does not cause linitis plastica.
**Option B:** Chronic gastric ulceration can lead to scarring and contraction of the stomach, but it does not result in the diffuse thickening characteristic of linitis plastica.
**Option C:** While lymphoma of the stomach can cause thickening of the stomach wall, it is not the primary cause of linitis plastica, and the correct answer includes diffuse carcinoma as well.

**Clinical Pearl / High-Yield Fact**
It's essential to differentiate between linitis plastica and other conditions that cause thickening of the stomach wall, such as chronic gastric ulceration or lymphoma. Linitis plastica often presents with early satiety, weight loss, and difficulty swallowing due to the rigid stomach.

**✓ Correct Answer: D. cd. Diffuse carcinoma stomach and Lymphoma of stomach.**